CIRCULATION STUDIO / REFERENCE LIBRARY

Works cited

Clinical foundations for the Lab, teaching cases, and waveform interpretation.

Adapted from V2 Hemodynamics MOR JD updated, CCM / Cardiology Half-day Series.

  1. Lilly. Pathophysiology of Heart Disease, 5th ed., 2011.
  2. Davidson et al. Cardiac Catheterization, in Braunwald’s Heart Disease, 9th ed., 2012.
  3. Murphy, Lloyd et al. Mayo Clinic Cardiology: Concise Textbook, 4th ed., 2013.
  4. Naidu et al. SCAI shock classification update, JACC, 2022.

Reference library

  1. Olshansky B, Chung MK, Pogwizd SM, Goldschlager N. Arrhythmia Essentials. 2nd ed. Elsevier; 2017. Ch. 1–2, 4–5, 7.
  2. Stouffer GA, editor. Cardiovascular Hemodynamics for the Clinician. Blackwell Publishing; 2008. pp. 26, 55, 71.
  3. Block B. Color Atlas of Ultrasound Anatomy. Thieme; 2004. pp. 88–89.
  4. Ragosta M. Textbook of Clinical Hemodynamics. 2nd ed. Elsevier; 2018. pp. 36, 39, 59–60.
  5. Steimle AE, Stevenson LW, Chelimsky-Fallick C, et al. Sustained hemodynamic efficacy of therapy tailored to reduce filling pressures in survivors with advanced heart failure. Circulation. 1997;96(4):1165–1172. doi:10.1161/01.CIR.96.4.1165 ↗

Waveform & physiology sources

Sources inform the synthetic teaching traces. Model responses are illustrative and not clinically validated.

  1. Valve sounds and splitting. Physiologic S2; RBBB and S1; abnormal S2. Opening-snap hemodynamics; valve opening and ejection clicks; prolapse and loading. Illustrative timing, not severity measurements.
  2. 12-lead ECG patterns. AHA/ACCF/HRS: conduction and ST–T interpretation. HRS ventricular arrhythmia consensus and ACC morphology reference. Synthetic examples; morphology does not prove origin.
  3. Waveform Quiz. Question patterns draw on the pressure, rhythm and valve references below; resistance calculations use mean pressure gradients and forward flow. Merck Manual: cardiac catheterization and normal pressure ranges. Randomized vitals are bounded teaching variations, not patient cases.
  4. ASD, PAPVR, PDA, VSD and Eisenmenger physiology. Gurvitz M, et al. 2025 ACC/AHA/HRS/ISACHD/SCAI Guideline for the Management of Adults With Congenital Heart Disease. Circulation. 2026;153:e115–e251. Sections 4.1, 4.4.6.
  5. ASD respiratory filling and S2 splitting. O’Toole JD, Reddy PS, Curtiss EI, Shaver JA. The mechanism of splitting of the second heart sound in atrial septal defect. Circulation. 1977;56:1047–1053. Original catheter study.
  6. Shunt flow measurements. 2022 ESC/ERS pulmonary hypertension guideline, section 5.1.12.1: saturation sampling and direct Fick in shunts; thermodilution is unsuitable with shunting.
  7. Squat, stand from squat and handgrip. American Heart Association, Hypertrophic Cardiomyopathy: Diagnosis and Clinical Implications of Structural Phenotypes, clinical teaching transcript; ESC, mitral disease and dynamic auscultation.
  8. Passive leg raise. Monnet X, Teboul JL. Passive leg raising: five rules, not a drop of fluid! Crit Care. 2015;19:18. Methodology.
  9. RA, RV, PA, wedge and LV pressure contours. Stouffer, 2008; Ragosta, 2018; AHA, Cardiac Hemodynamics; ATS, PA waveform teaching.
  10. ECG timing, conduction and pacing. Olshansky et al., Arrhythmia Essentials. AHA/ACCF/HRS ECG standardization, part III; 2019 ESC SVT guidelines.
  11. Valsalva phase responses. Goldstein DS, Cheshire WP Jr. Beat-to-beat blood pressure and heart rate responses to the Valsalva maneuver. Clin Auton Res. 2017;27:361–367. Physiology review. Echocardiographic evaluation in healthy subjects and patients with and without heart failure.
  12. Wiggers diagrams and pressure–volume loops. Klabunde RE. CV Physiology: ventricular pressure–volume relationships, effects of preload, afterload and inotropy, and cardiac cycle and heart sounds.
  13. Post-PVC response in HOCM. Brockenbrough EC, Braunwald E, Morrow AG. A hemodynamic technic for the detection of hypertrophic subaortic stenosis. Circulation. 1961;23:189–194. Original report.
  14. Combined valve physiology. Bansal et al., serial LV outflow obstruction (2021); Salustri & Almaghrabi, mitral hemodynamics (2018).
  15. Carabello pullback sign. Carabello BA, Barry WH, Grossman W. Changes in arterial pressure during left heart pullback in patients with aortic stenosis: a sign of severe aortic stenosis. Am J Cardiol. 1979;44:424–427. Study.
  16. Constriction versus restriction. Talreja DR, Nishimura RA, Oh JK, Holmes DR. Constrictive pericarditis in the modern era: novel criteria for diagnosis in the cardiac catheterization laboratory. J Am Coll Cardiol. 2008;51:315–319. Study.
  17. IABP pressure contours and timing. Getinge. Cardiosave IABP Operation/Transport Quick Reference Guide, software B. Manufacturer guide.
  18. V-A ECMO, arterial pulsatility and LV loading. Lorusso R, et al. ELSO interim guidelines for venoarterial extracorporeal membrane oxygenation in adult cardiac patients. ASAIO J. 2021;67:827–844. Guideline. Mourad M, et al. Pulse pressure and end-tidal carbon dioxide for monitoring low native cardiac output during veno-arterial ECLS. Crit Care. 2020;24:569. Prospective study.
  19. Impella flow and unloading. Abiomed. Impella Ventricular Support Systems: Instructions for Use & Clinical Reference Manual. FDA-hosted labeling.
  20. Supported chamber pressures and pressure–volume loops. Donker DW, Brodie D, Henriques JPS, Broomé M. Left ventricular unloading during veno-arterial ECMO: a simulation study. ASAIO J. 2019;65:11–20. Simulation study.
  21. Arterial reservoir model during continuous support. Westerhof N, Lankhaar JW, Westerhof BE. The arterial Windkessel. Med Biol Eng Comput. 2009;47:131–141. Model review.
  22. Plethysmography and respiratory timing. Allen J. Photoplethysmography and its application in clinical physiological measurement. Physiol Meas. 2007;28:R1–R39. Review. University of Iowa, Ventilator 101: respiratory rate and I:E timing.
  23. Case pulse oximetry. FDA. Pulse Oximeters.
  24. Disease pressure and resistance targets. 2022 ESC/ERS pulmonary hypertension guidelines and 2020 ACC/AHA valvular heart disease guideline.
Measurement assumptions

BSA 2.0 m². Estimated MAP = (SBP + 2 × DBP) / 3. SVR uses displayed CVP and output; recorded PA means may differ from arithmetic estimates.

ScvO₂ ≠ SvO₂. Thermodilution is independent of assumed Fick oxygen consumption. PAWP and PCWP both mean wedge pressure.

Complete list of sources

Identifiable references from the Lab, teaching pages, cases, quiz, and earlier revisions. Original teaching assumptions are not validated patient data.

Books & original teaching material9
  1. V2 Hemodynamics MOR JD updated Joshua Durbin. CCM / Cardiology Half-day Series. Supplied teaching slides and case material.
  2. Pathophysiology of Heart Disease Lilly LS. 5th ed. 2011.
  3. Cardiac Catheterization Davidson et al. In: Braunwald’s Heart Disease. 9th ed. 2012. Reference retained from the supplied slides.
  4. Mayo Clinic Cardiology: Concise Textbook Murphy JG, Lloyd MA, editors. 4th ed. 2013.
  5. Cardiovascular Hemodynamics for the Clinician Stouffer GA, editor. Blackwell; 2008. Supplied PDF; pp. 22–24 and 67–71 inform the stationary catheter and atrial teaching traces.
  6. Textbook of Clinical Hemodynamics Ragosta M. 2nd ed. Elsevier; 2018. Supplied PDF.
  7. Color Atlas of Ultrasound Anatomy Block B. Thieme; 2004. Supplied PDF.
  8. Arrhythmia Essentials Olshansky B, Chung MK, Pogwizd SM, Goldschlager N. 2nd ed. Elsevier; 2017. Supplied PDF.
  9. Hemodynamic Rounds: Interpretation of Cardiac Pathophysiology from Pressure Waveform Analysis Kern MJ, Lim MJ, Goldstein JA, editors. 4th ed. Wiley; 2018.
Hemodynamics, measurement & waveforms59
  1. How the Heart Works: How Blood Flows through the Heart National Heart, Lung, and Blood Institute. Last updated June 25, 2025. Normal circulation route and chamber roles. Reviewed 2026-09-20.
  2. How the Heart Works: How the Heart Beats National Heart, Lung, and Blood Institute. Last updated June 25, 2025. Introductory heart rate and systolic/diastolic blood-pressure definitions. Reviewed 2026-09-20.
  3. Blood Flow, Blood Pressure, and Resistance Betts JG, Young KA, Wise JA, et al. Anatomy and Physiology 2e. OpenStax. Pressure gradients, cardiac output and vascular resistance. Reviewed 2026-09-20.
  4. Cardiac Muscle and Electrical Activity Betts JG, Young KA, Wise JA, et al. Anatomy and Physiology 2e. OpenStax. ECG voltage recording and P, QRS and T electrical events. Reviewed 2026-09-20.
  5. Feasibility of continuous oxygen delivery and cardiac output measurement by application of the Fick principle Feustel PJ, et al. Am J Respir Crit Care Med. 1994;149:751–758. Oxygen content and Fick flow relationships.
  6. Thermodilution Assessment of Cardiac Index in Patients With Tricuspid Regurgitation Sternberg ME, et al. J Invasive Cardiol. 2023;35:E122–E125. TR does not imply a universal thermodilution bias.
  7. Underestimation of cardiac output by thermodilution in patients with tricuspid regurgitation Cigarroa RG, et al. Am J Med. 1989;86:417–420. Historical under-reading example; not a fixed correction factor.
  8. Right heart catheterization in clinical practice: a review of basic physiology and important issues relevant to interpretation Del Rio-Pertuz G, Nugent K, Argueta-Sosa E. Am J Cardiovasc Dis. 2023;13:122–137.
  9. Pulmonary artery catheterisation Gilbert-Kawai N, Chen R, Patel S. BJA Educ. 2024;24:447–457.
  10. Cardiac Hemodynamics Yeghiazarians Y. American Heart Association, 2014. Pressure waveform teaching.
  11. Pulmonary artery hemodynamics tracing American Thoracic Society. 2021 teaching resource.Previously cited PDF; the original link may now redirect.
  12. Cardiac Catheterization Merck Manual Professional Edition.
  13. Normal Pressures in the Heart and Great Vessels Merck Manual Professional Edition. Supplemental ventricular reference ranges; LVEDP 5–12 mmHg.
  14. Methods in pharmacology: measurement of cardiac output Geerts BF, Aarts LP, Jansen JR. Br J Clin Pharmacol. 2011;71:316–330.
  15. Thermodilution and Fick cardiac outputs differ: impact on pulmonary hypertension evaluation Fares WH, et al. Can Respir J. 2012;19:261–266.
  16. Time to Calm the Fick Down? A Systematic Review and Meta-Analysis of Thermodilution Compared to Direct Fick in Tricuspid Regurgitation Abualsaud R, et al. CJC Open. 2024;6:1138–1144.
  17. Calculating FICK Cardiac Output and Input StatPearls. NCBI Bookshelf.
  18. Measuring cardiac output in critically ill patients: disagreement between thermodilution-, calculated-, expired gas-, and oxygen consumption-based methods Sherman MS, Kosinski R, Paz HL, Campbell D. Cardiology. 1997;88:19–25.
  19. Features Associated With Discordance Between Pulmonary Arterial Wedge Pressure and Left Ventricular End Diastolic Pressure in Clinical Practice: Implications for Pulmonary Hypertension Classification Hemnes AR, et al. Chest. 2018;154:1099–1107.
  20. Accuracy of left atrial and pulmonary artery wedge pressure in pure mitral regurgitation in predicting left ventricular end-diastolic pressure Haskell RJ, French WJ. Am J Cardiol. 1988;61:136–141.
  21. Sustained hemodynamic efficacy of therapy tailored to reduce filling pressures in survivors with advanced heart failure Steimle AE, Stevenson LW, Chelimsky-Fallick C, et al. Circulation. 1997;96:1165–1172. Supplied EPUB.
  22. Constrictive pericarditis in the modern era: novel criteria for diagnosis in the cardiac catheterization laboratory Talreja DR, Nishimura RA, Oh JK, Holmes DR. JACC. 2008;51:315–319.
  23. A hemodynamic technic for the detection of hypertrophic subaortic stenosis Brockenbrough EC, Braunwald E, Morrow AG. Circulation. 1961;23:189–194.
  24. Changes in arterial pressure during left heart pullback in patients with aortic stenosis: a sign of severe aortic stenosis Carabello BA, Barry WH, Grossman W. Am J Cardiol. 1979;44:424–427. Catheter-obstruction pullback sign.
  25. The mechanism of splitting of the second heart sound in atrial septal defect O’Toole JD, Reddy PS, Curtiss EI, Shaver JA. Circulation. 1977;56:1047–1053.
  26. The arterial Windkessel Westerhof N, Lankhaar JW, Westerhof BE. Med Biol Eng Comput. 2009;47:131–141.
  27. How to measure blood pressure using an arterial catheter: a systematic 5-step approach Saugel B, et al. Critical Care. 2020;24:172.
  28. Intra-arterial blood pressure measurement: sources of error and solutions Devasahayam S, et al. Med Biol Eng Comput. 2022;60:1123–1138.
  29. Direct blood pressure measurement—dynamic response requirements Gardner RM. Anesthesiology. 1981;54:227–236.
  30. First heart sound and ejection sounds: echocardiographic and phonocardiographic correlation with valvular events Waider W, Craige E. Am J Cardiol. 1975;35:346–356.
  31. Cineradiographic studies of the early systolic click in aortic valve stenosis Epstein EJ et al. Circulation. 1965;31:842–853.
  32. Ejection clicks Jacobs WR. Clinical Methods. 3rd ed. 1990. Chapter 28.
  33. Noninvasive/invasive correlates of exaggerated ventricular interdependence in cardiac tamponade Shaver JA, Reddy PS, Curtiss EI, Ziady GM, Reddy SC. J Cardiol. 2001;37 Suppl 1:71–76.
  34. Mechanism of electrical alternans in patients with pericardial effusion Rinkenberger RL, Polumbo RA, Bolton MR, Dunn M. Cathet Cardiovasc Diagn. 1978;4:63–70.
  35. Proportional relations between systolic, diastolic and mean pulmonary artery pressure are explained by vascular properties Kind T, Faes TJC, Vonk-Noordegraaf A, Westerhof N. Cardiovasc Eng Technol. 2011;2:15–23.
  36. Golden ratio and the proportionality between pulmonary pressure components in pulmonary arterial hypertension Chemla D, et al. Chest. 2019;155:991–998.
  37. Measuring Valve Gradients and Areas Dean LS, Kern MJ. J Soc Cardiovasc Angiogr Interv. 2022;1:100433.
  38. Recommendations for Improving and Standardizing Vascular Research on Arterial Stiffness Townsend RR, Wilkinson IB, Schiffrin EL, et al. AHA scientific statement. Hypertension. 2015;66:698–722.
  39. Haemodynamic factors influencing opening snap interval in mitral stenosis Ebringer R, Pitt A, Anderson ST. Br Heart J. 1970;32:350–354.
  40. The second sound–mitral opening snap interval during exercise in the evaluation of mitral stenosis Delman AJ, Gordon GM, Stein E, Escher DJ. Circulation. 1966;33:399–403.
  41. Postural changes in left ventricular and mitral valvular dynamics in the systolic click–late systolic murmur syndrome Fontana ME, Wooley CF, Leighton R, Lewis RP. Circulation. 1975;51:165–173.
  42. Swan-Ganz True Size Thermodilution Catheters Edwards Lifesciences. Instructions for use, DOC-0552125A. Figure 2: catheter pressure progression.
  43. Mitral valve disease: correlation between the most important echocardiographic parameters and haemodynamics Salustri A, Almaghrabi A. ESC e-Journal of Cardiology Practice. 2018;16.
  44. Tricuspid Stenosis Armstrong GP; reviewed by Howlett JG. Merck Manual Professional Edition. Updated June 2025.
  45. Haemodynamic Interplay Between Concomitant Left Ventricular Outflow Tract Obstruction and Aortic Stenosis Bansal P, Lodhi H, Mathews A, et al. Interventional Cardiology Review. 2021;16:e11.
  46. Aortic Stenosis With Dynamic Left Ventricular Outflow Obstruction: Diagnostic and Management Challenges—A Case Series Qian F, McGregor P-C, Latifi AN, Aragam J. CASE. 2025;9:9–18.
  47. Managing Left Ventricular Outflow Tract Obstruction in Combined Aortic Stenosis and Hypertrophic Cardiomyopathy Shi M, Saleh D, Leya MV, Puthumana JJ, Flaherty JD, Choudhury L. JACC: Case Reports. 2024;29:102653.
  48. Cardiac tamponade in association with an atrial septal defect: echocardiographic Doppler and hemodynamic observations Joffe II, Douglas PS. J Am Soc Echocardiogr. 1996;9(6):909–914.
  49. The First Heart Sound Felner JM. Clinical Methods. 3rd ed. 1990; chapter 22.
  50. The Second Heart Sound Felner JM. Clinical Methods. 3rd ed. 1990; chapter 23.
  51. Mechanism of normal splitting of the second heart sound Curtiss EI, Matthews RG, Shaver JA. Circulation. 1975;51:157–164.
  52. Complete right bundle-branch block: echophonocardiographic study of first heart sound and right ventricular contraction times Brooks N, Leech G, Leatham A. Br Heart J. 1979;41:637–646.
  53. Physiology and cardiovascular effect of severe tension pneumothorax in a porcine model Nelson D, et al. J Surg Res. 2013;184:450–457. Animal physiology; illustrative obstructive-flow model and quiz.
  54. Thoracic trauma WSES-AAST guidelines Coccolini F, et al. World J Emerg Surg. 2025;20:78. Pleural injuries: pneumothorax and hemothorax.
  55. Impact of Concomitant Mitral Regurgitation on the Hemodynamic Indicators of Aortic Stenosis Šeman M, Stephens AF, Walton A, et al. J Am Heart Assoc. 2023;12:e025648.MR reduces forward flow and measured aortic gradients.
  56. Mitral valve disease: effects of exercise and drugs on echocardiographic parameters Brandt RR, Nishimura RA. ESC e-Journal of Cardiology Practice. 2018;16.Flow dependence and mixed mitral disease.
  57. Hemodynamic consequences of afterload reduction in patients with chronic aortic regurgitation Bolen JL, Alderman EL. Circulation. 1976;53:879–883.Variable forward-flow and regurgitant responses to nitroprusside.
  58. Cardiovascular effects of inhaled nitric oxide in patients with left ventricular dysfunction Loh E, Stamler JS, Hare JM, Loscalzo J, Colucci WS. Circulation. 1994;90:2780–2785.Reduced PVR can accompany increased wedge pressure without improved output.
  59. Influence of inhaled nitric oxide on systemic flow and ventricular filling pressure in patients receiving mechanical circulatory assistance Hare JM, et al. Circulation. 1997;95:2250–2253.Pulmonary redistribution when systemic flow cannot increase.
Guidelines & clinical assessment26
  1. 2022 ESC/ERS Guidelines for the diagnosis and treatment of pulmonary hypertension Humbert M, et al. Eur Heart J. 2022;43:3618–3731. Table 11: normal RHC pressures, flow and resistance; PH definitions.Table 11 supplies available reference ranges in the summary and model wiki; illustrative display alerts are separate from diagnostic definitions.
  2. 2025 ACC/AHA/HRS/ISACHD/SCAI Guideline for the Management of Adults With Congenital Heart Disease Gurvitz M, et al. Circulation. 2026;153:e115–e251.
  3. 2020 ACC/AHA Guideline for the Management of Patients With Valvular Heart Disease American College of Cardiology / American Heart Association.Valvular and mixed-lesion physiology informs the model reference; numerical interaction coefficients and severity endpoints are synthetic.
  4. 2024 AHA/ACC multisociety Guideline for the Management of Hypertrophic Cardiomyopathy American Heart Association / American College of Cardiology.
  5. 2025 Concise Clinical Guidance: An ACC Expert Consensus Statement on the Evaluation and Management of Cardiogenic Shock Sinha SS, Morrow DA, Kapur NK, et al. JACC. 2025;85:1618–1641. Shock recognition and congestion profiles.Shock context for the model reference; the software’s color and deterioration rules are illustrative, not a guideline severity score.
  6. SCAI SHOCK Stage Classification Expert Consensus Update: A Review and Incorporation of Validation Studies Naidu SS, et al. JACC. 2022;79:933–946.A–E stage descriptions inform the original halfday shock diagram.
  7. Mixed Cardiogenic–Vasodilatory Shock: Current Insights and Future Directions Jentzer JC, et al. JACC: Advances. 2025;4:101432.
  8. Right ventricular failure ESC e-Journal of Cardiology Practice. Vol. 14.
  9. Cardiac tamponade: a clinical challenge ESC e-Journal of Cardiology Practice. Vol. 15.
  10. Pericardiocentesis in cardiac tamponade: indications and practical aspects ESC e-Journal of Cardiology Practice. Vol. 15.
  11. 2019 ESC Guidelines on Acute Pulmonary Embolism European Society of Cardiology.
  12. Shock Procter LD; peer review by Spain DA. MSD / Merck Manual Professional Edition. Updated July 2026.
  13. Surviving Sepsis Campaign: International Guidelines for Management of Sepsis and Septic Shock 2021 Society of Critical Care Medicine / European Society of Intensive Care Medicine.
  14. KDIGO Clinical Practice Guideline for Acute Kidney Injury Kidney International Supplements. 2012;2.
  15. Emergency treatment of anaphylaxis Resuscitation Council UK. 2021 guideline and supporting resources.
  16. The Sepsis Manual UK Sepsis Trust. 7th ed. 2024.
  17. Contemporary Management of Cardiogenic Shock American Heart Association. Circulation. 2017.
  18. 2025 ESC/EACTS valvular heart disease guideline ESC/EACTS. European Heart Journal. 2025.
  19. MitraClip safety and effectiveness FDA. PMA P100009. 2013.
  20. TriClip G4 safety and effectiveness FDA. PMA P230007. 2024.
  21. Invasive hemodynamics after MitraClip Bednar et al. BioMed Research International. 2016.
  22. Medical Therapy of Acute Myocardial Infarction by Application of Hemodynamic Subsets Forrester JS, Diamond G, Chatterjee K, Swan HJC. N Engl J Med. 1976;295:1356–1362.
  23. 2022 AHA/ACC/HFSA Guideline for the Management of Heart Failure Heidenreich PA, et al. Circulation. 2022;145:e895–e1032.Official guideline slide set
  24. The European guideline on management of major bleeding and coagulopathy following trauma: sixth edition Rossaint R, et al. Critical Care. 2023;27:80.
  25. Diagnosis and management of pulmonary hypertension due to left heart disease or pulmonary disease European Society of Cardiology. CardioPractice, 2026. Postcapillary pressure elevation versus pulmonary vascular disease.
  26. ISHLT/HFSA Guideline on Acute Mechanical Circulatory Support International Society for Heart and Lung Transplantation / Heart Failure Society of America. 2023.
Rhythm & resuscitation12
  1. AHA/ACCF/HRS Recommendations for the Standardization and Interpretation of the Electrocardiogram: Part III, Intraventricular Conduction Disturbances Surawicz B, et al. Circulation. 2009.
  2. AHA/ACCF/HRS ECG Interpretation: Part IV, ST Segment, T and U Waves, and QT Interval Rautaharju PM, Surawicz B, Gettes LS. J Am Coll Cardiol. 2009;53:982–991.
  3. 2019 HRS/EHRA/APHRS/LAHRS Expert Consensus on Catheter Ablation of Ventricular Arrhythmias Cronin EM, et al. 2019. ECG morphology and fascicular ventricular tachycardia.
  4. Premature Ventricular Contractions in Athletes: Insight into Evaluation and Management Darden D, Prutkin JM. American College of Cardiology. 2022.
  5. AHA/ACCF/HRS ECG Interpretation: Part V, Cardiac Chamber Hypertrophy Hancock EW, et al. Circulation. 2009;119:e251–e261. Atrial P-wave morphology.
  6. 2018 ACC/AHA/HRS Guideline: Bradycardia and Cardiac Conduction Delay Kusumoto FM, et al. Circulation. 2019;140:e382–e482. PR interval and AV conduction.
  7. 2019 ESC Guidelines for the management of patients with supraventricular tachycardia Brugada J, et al. Eur Heart J. 2020;41:655–720.
  8. 2023 ACC/AHA/ACCP/HRS Guideline for the Diagnosis and Management of Atrial Fibrillation American College of Cardiology / American Heart Association.
  9. Adult Advanced Life Support American Heart Association. Guidelines for CPR and Emergency Cardiovascular Care. 2025.
  10. Adult Cardiac Arrest Algorithm American Heart Association. 2025.
  11. Tachycardia recognition and diagnosis from changes in right atrial pressure waveform—a feasibility study Kaye GC, Astridge P, Perrins J. Pacing Clin Electrophysiol. 1991;14:1384–1392.
  12. The effect of atropine in vasovagal syncope induced by head-up tilt testing Santini M, Ammirati F, Colivicchi F, Gentilucci G, Guido V. Eur Heart J. 1999;20:1745–1751.
Maneuvers & the cardiac cycle21
  1. Hypertrophic Cardiomyopathy: Diagnosis and Clinical Implications of Structural Phenotypes American Heart Association. Educational podcast transcript.
  2. Mitral valve disease: clinical features focusing on auscultatory findings, including auscultation of mitral valve prolapse ESC e-Journal of Cardiology Practice. Vol. 16.
  3. Cardiac Auscultation Merck Manual Professional Edition.
  4. Passive leg raising: five rules, not a drop of fluid! Monnet X, Teboul JL. Crit Care. 2015;19:18.
  5. Beat-to-beat blood pressure and heart rate responses to the Valsalva maneuver Goldstein DS, Cheshire WP Jr. Clin Auton Res. 2017;27:361–367.
  6. Echocardiographic evaluation of the Valsalva maneuver in healthy subjects and patients with and without heart failure Parisi AF, et al. Circulation. 1976;54:921–927.
  7. Valsalva maneuver Shindler D. Rutgers Robert Wood Johnson Medical School. Echocardiography teaching resource.
  8. Factors Regulating Arterial Blood Pressure Klabunde RE. Cardiovascular Physiology Concepts (CV Physiology).
  9. Cardiac Afterload Klabunde RE. Cardiovascular Physiology Concepts (CV Physiology).
  10. Ventricular Pressure–Volume Relationship Klabunde RE. Cardiovascular Physiology Concepts. Revised November 2023. Valve timing and ventricular filling.
  11. Interdependent Effects of Preload, Afterload and Inotropy on Ventricular Pressure–Volume Loops Klabunde RE. Cardiovascular Physiology Concepts (CV Physiology).
  12. Cardiac Cycle Klabunde RE. Cardiovascular Physiology Concepts. Revised November 2023. Wiggers timing and atrial-pressure interpretation.
  13. Ventricular Pressure–Volume Loop Changes in Valve Disease Klabunde RE. Cardiovascular Physiology Concepts. Revised January 2023.
  14. Valvular Stenosis Klabunde RE. Cardiovascular Physiology Concepts. Revised 2023.
  15. Aortic Stenosis Merck Manual Professional Edition. Systemic pressure and ventricular function.
  16. Mitral Regurgitation Merck Manual Professional. Acute and chronic chamber responses.
  17. Tricuspid Regurgitation Armstrong GP. Merck Manual Professional. Updated October 2025.
  18. Pulmonary Regurgitation Merck Manual Professional. RV volume loading.
  19. Pulmonary Stenosis Merck Manual Professional. RV pressure loading.
  20. Aortic Regurgitation: Pressure–Volume Loop Klabunde RE. Cardiovascular Physiology Concepts. Revised January 2023.
  21. Mitral Regurgitation: Pressure–Volume Loop Klabunde RE. Cardiovascular Physiology Concepts. Revised February 2024.
Mechanical circulatory support12
  1. Intra-Aortic Balloon Pumps Stanford Cardiovascular Anesthesia.
  2. Cardiosave IABP Operation/Transport Quick Reference Guide Getinge. Software B.
  3. Beat-to-beat effects of intraaortic balloon pump timing on left ventricular performance in patients with low ejection fraction Schreuder JJ, et al. Ann Thorac Surg. 2005;79:872–880.
  4. ELSO Interim Guidelines for Venoarterial Extracorporeal Membrane Oxygenation in Adult Cardiac Patients Lorusso R, et al. ASAIO J. 2021;67:827–844. doi:10.1097/MAT.0000000000001510.Circuit flow, vascular load and LV unloading.
  5. Impella Ventricular Support Systems: Summary of Safety and Effectiveness Data US Food and Drug Administration / Abiomed. PMA P140003/S004. 2016.
  6. Pulse pressure and end-tidal carbon dioxide for monitoring low native cardiac output during veno-arterial ECLS Mourad M, et al. Crit Care. 2020;24:569.
  7. Left ventricular unloading during veno-arterial ECMO: a simulation study Donker DW, Brodie D, Henriques JPS, Broomé M. ASAIO J. 2019;65:11–20.
  8. Intra-Aortic Balloon Pump Exacerbates Left Ventricular Outflow Tract Obstruction in a Patient With Takotsubo and Hypertrophic Cardiomyopathy Griffin M, et al. CASE. 2023;7:502–507.
  9. Bard Sheathless Intra-Aortic Balloon Catheters: 510(k) Summary US Food and Drug Administration / Bard. K981660. Device labeling and contraindications.
  10. Pathophysiology of Heart Failure Klabunde RE. Cardiovascular Physiology Concepts. Revised November 2023.
  11. Overview, Indications, and Step-by-Step Techniques for Hemodynamic Support Devices Kandasamy VV, John AG, Singh V. ACC Coronary Interventions Handbook, Chapter 11. Accessed September 10, 2026.
  12. Comparative hemodynamic effects of Impella CP and TandemHeart Weil BR et al. JACC Cardiovasc Interv. 2016;9:2292–2303. Porcine infarction study; ventricular unloading and PV responses.
Lungs, oxygenation & imaging20
  1. Photoplethysmography and its application in clinical physiological measurement Allen J. Physiol Meas. 2007;28:R1–R39.
  2. Ventilator 101: settings, waveforms and auto-PEEP University of Iowa. Ventilator 101.
  3. Respiratory Rate and Pattern Braun SR. In: Clinical Methods. 3rd ed. Butterworths; 1990. Chapter 43.
  4. Pulse Oximeters US Food and Drug Administration.
  5. Pulmonary Edema Merck Manual Professional Edition.
  6. Unilateral Pulmonary Edema in Patients With Acute Mitral Regurgitation Caused by Chordal Rupture Nishimura Y, et al. Circ Rep. 2022;4:571–578.
  7. Differentiating Acute Pulmonary Edema and Asthma With the Lung Curtain Swing vs Time Graph: A Novel Application of Anatomical M-Mode Evaluation of Lung Swing Gunasegaren M, Lee CH. Chest. 2026;169:e61–e66.Previously linked respiratory imaging report; not validation of simulated respiratory-rate targets.
  8. Guidelines for Performing a Comprehensive Transthoracic Echocardiographic Examination in Adults American Society of Echocardiography. 2019. Used for earlier echo-orientation content.
  9. Guidelines for the Evaluation of Prosthetic Valve Function With Cardiovascular Imaging Zoghbi WA, et al. American Society of Echocardiography. 2024.
  10. Guidelines for the Echocardiographic Assessment of the Right Heart in Adults and Special Considerations in Pulmonary Hypertension Mukherjee M, Rudski LG, et al. American Society of Echocardiography. 2025.
  11. Recommendations for Noninvasive Evaluation of Native Valvular Regurgitation Zoghbi WA, Adams D, Bonow RO, et al. ASE / SCMR. JASE. 2017;30:303–371.Regurgitant burden, loading conditions and chamber response.
  12. How Far Is the Sternal Angle from the Mid-right Atrium? Seth R, Magner P, Matzinger F, van Walraven C. J Gen Intern Med. 2002;17:852–856.
  13. Cardiovascular devices The Radiology Assistant. Chest radiographic device anatomy.
  14. AARC Clinical Practice Guideline: Patient-Ventilator Assessment American Association for Respiratory Care. Respir Care. 2024;69:1042–1054.Tidal volume, plateau pressure, PEEP and auto-PEEP assessment.
  15. Mechanical Ventilation in Adult Patients with Acute Respiratory Distress Syndrome Fan E, Del Sorbo L, Goligher EC, et al. ATS/ESICM/SCCM. Am J Respir Crit Care Med. 2017;195:1253–1263.Lung-protective volume and plateau-pressure guidance.
  16. Oxygen Transport Pittman RN. Regulation of Tissue Oxygenation. Morgan & Claypool; 2011. Chapter 4.Oxygen content and the Hill dissociation relationship.
  17. Teaching an intuitive derivation of the clinical alveolar equations: mass balance as a fundamental physiological principle Wang MC, Corbridge TC, McCrimmon DR, Walter JM. Adv Physiol Educ. 2020;44:145–152.Alveolar ventilation, dead space and gas mass balance.
  18. Deadspace and the single breath test for carbon dioxide during anaesthesia and artificial ventilation Fletcher R, Jonson B. Br J Anaesth. 1984;56:109–119.Tidal volume, frequency and dead-space effects.
  19. Dynamic handgrip exercise for the evaluation of mitral valve regurgitation Alachkar MN, et al. Int J Cardiovasc Imaging. 2021;37:891–902.Variable MR response to loading.
  20. A Thrilling Precordial Honk Amoroso NS, Som S, Carabello BA. American College of Cardiology. 2016.Dynamic MR and prolapse respond differently to changes in loading.
Medication prescribing information22
  1. Isoproterenol hydrochloride injection DailyMed. US National Library of Medicine. Prescribing information.
  2. Ephedrine sulfate injection DailyMed. US National Library of Medicine. Prescribing information.
  3. Amiodarone hydrochloride injection DailyMed. US National Library of Medicine. Prescribing information.
  4. Procainamide hydrochloride injection DailyMed. US National Library of Medicine. Prescribing information.
  5. Lidocaine hydrochloride and dextrose injection DailyMed. US National Library of Medicine. Prescribing information.
  6. Vasopressin injection DailyMed. US National Library of Medicine. Prescribing information.Additional pharmacology label
  7. Phenylephrine hydrochloride injection DailyMed. US National Library of Medicine. Prescribing information.Additional pharmacology label
  8. Milrinone lactate injection DailyMed. US National Library of Medicine. Prescribing information.Additional pharmacology label
  9. Metoprolol tartrate injection DailyMed. US National Library of Medicine. Prescribing information.Earlier cited label
  10. Digoxin injection DailyMed. US National Library of Medicine. Prescribing information.Earlier cited label
  11. Furosemide injection Hospira. DailyMed prescribing information. Revised October 2024; label updated May 2026.Additional pharmacology label
  12. Nitroglycerin injection DailyMed. US National Library of Medicine. Prescribing information.Sublingual pharmacology label
  13. Nitroprusside in critically ill patients with left ventricular dysfunction and aortic stenosis Khot UN, et al. N Engl J Med. 2003;348:1756–1763. Selected, invasively monitored LV failure; hypotension and pressor/inotrope dependence excluded.
  14. Complications Associated With Nitrate Use in Patients Presenting With Acute Pulmonary Edema and Concomitant Moderate or Severe Aortic Stenosis Claveau D, et al. Ann Emerg Med. 2015;66:355–362.e1. Retrospective evidence; vasodilator tolerance depends on context.
  15. Sodium nitroprusside injection DailyMed. US National Library of Medicine. Prescribing information.Additional pharmacology label
  16. Epoprostenol injection DailyMed. US National Library of Medicine. Prescribing information.Additional pharmacology label
  17. INOmax (nitric oxide gas) DailyMed. US National Library of Medicine. Prescribing information.Additional pharmacology labelLV dysfunction: pulmonary edema and increased wedge-pressure warning.
  18. Amyl nitrite inhalant DailyMed. US National Library of Medicine. Prescribing information.
  19. Epinephrine injection DailyMed. US National Library of Medicine. Prescribing information.
  20. Dopamine hydrochloride injection DailyMed. US National Library of Medicine. Prescribing information.
  21. Dobutamine injection DailyMed. US National Library of Medicine. Prescribing information.
  22. Norepinephrine injection DailyMed. US National Library of Medicine. Prescribing information.Vascular resistance and pressor action.
PEEP, pressure transmission & heart–lung interactions14
  1. Positive Pressure Ventilation in the Cardiac Intensive Care Unit Alviar CL, Miller PE, McAreavey D, et al. JACC. 2018;72:1532–1553.Heart–lung relationships inform the model wiki; fixed pressure transmission, recruitment and response coefficients are teaching assumptions.
  2. Effect of positive end-expiratory pressure on right ventricular function in humans Pinsky MR, Desmet JM, Vincent JL. Am Rev Respir Dis. 1992;146:681–687.
  3. Cardiac performance in response to PEEP in patients with cardiac dysfunction Grace MP, Greenbaum DM. Crit Care Med. 1982;10:358–360.
  4. Hemodynamic alterations with positive end-expiratory pressure: the contribution of the pulmonary vasculature Hobelmann CF Jr, Smith DE, Virgilio RW, et al. J Trauma. 1975;15:951–959.
  5. Clinical review: Positive end-expiratory pressure and cardiac output Luecke T, Pelosi P. Crit Care. 2005;9:607–621.
  6. Guide to the SI: pressure conversion factors NIST SP 811, Appendix B.9. Conventional cmH₂O and mmHg.
  7. Interaction between respiration and right versus left ventricular volumes at rest and during exercise: a real-time cardiac magnetic resonance study Claessen G, Claus P, Delcroix M, et al. Am J Physiol Heart Circ Physiol. 2014;306:H816–H824.
  8. Prevention of complications in the cardiac intensive care unit Fordyce CB et al. AHA scientific statement. Circulation. 2020;142:e379–e406. Ventilation, RV loading and LV unloading.
  9. Cardiovascular effects of positive-pressure ventilation in normal subjects Cassidy SS et al. J Appl Physiol. 1979;47:453–461. Measured biventricular and output responses to PEEP.
  10. Respiratory-Cardiovascular Interactions During Mechanical Ventilation: Physiology and Clinical Implications Kreit J. Compr Physiol. 2022;12:3425–3448.
  11. Heart-lung interactions during mechanical ventilation: the basics Mahmood SS, Pinsky MR. Ann Transl Med. 2018;6:349.
  12. Extent to which pulmonary vascular responses to PCO₂ and PO₂ play a functional role within the healthy human lung Dorrington KL, Balanos GM, Talbot NP, Robbins PA. J Appl Physiol. 2010;108:1084–1096.
  13. Acute Effects of Positive Airway Pressure on Functional Mitral Regurgitation in Patients with Systolic Heart Failure Kato T, et al. Front Physiol. 2017;8:921.Functional MR may decrease; forward-flow response varies.
  14. Effect of PEEP, blood volume, and inspiratory hold maneuvers on venous return Berger D, et al. Am J Physiol Heart Circ Physiol. 2016;311:H794–H806.
Biventricular diagrams & valve pressure gradients5
  1. SCAI/HFSA expert consensus document on the use of invasive hemodynamics for the diagnosis and management of cardiovascular disease Sorajja P, Borlaug BA, Dimas VV, et al. Catheter Cardiovasc Interv. 2017;89:E233–E247. Simultaneous chamber-pressure comparison.
  2. Methods for measuring right ventricular function and hemodynamic coupling with the pulmonary vasculature Bellofiore A, Chesler NC. Ann Biomed Eng. 2013;41:1384–1398.
  3. Valvular insufficiency (regurgitation) Klabunde RE. Cardiovascular Physiology Concepts.
  4. Physiology, pulse pressure Homan TD, Bordes SJ, Cichowski E. StatPearls. Updated July 10, 2023.
  5. Invasive right ventricular pressure–volume analysis Brener MI et al. Circ Heart Fail. 2022;15:e009101. Principles and practical recommendations.
Non-sustained ventricular tachycardia4
  1. 2022 ESC Guidelines for ventricular arrhythmias and prevention of sudden cardiac death Zeppenfeld K, et al. Eur Heart J. 2022;43:3997–4126.
  2. Incomplete filling and incoordinate contraction as mechanisms of hypotension during ventricular tachycardia in man Lima JAC, et al. Circulation. 1983;68:928–938.
  3. Amiodarone hydrochloride injection: prescribing information DailyMed. Ventricular arrhythmia suppression, hypotension and conduction precautions.
  4. Lidocaine hydrochloride injection: prescribing information DailyMed. Acute ventricular arrhythmias and conduction precautions.
Sedation and cardiorespiratory interactions8
  1. Propofol injectable emulsion: prescribing information DailyMed. Maintenance infusion, cardiovascular depression and ventilation.
  2. Ketamine hydrochloride injection: prescribing information DailyMed. Sympathetic responses, catecholamine depletion and respiratory precautions.
  3. Midazolam hydrochloride injection: prescribing information DailyMed. Sedation, opioid interactions and adult infusion dosing.
  4. Dexmedetomidine injection: prescribing information DailyMed. Maintenance infusion, bradycardia and hypotension; loading is not simulated.
  5. Fentanyl citrate injection: prescribing information DailyMed. Respiratory depression, opioid-sedative interactions and cardiovascular effects.
  6. Effects of hypercapnia on hemodynamic, inotropic, lusitropic, and electrophysiologic indices in humans Kiely DG, Cargill RI, Lipworth BJ. Chest. 1996;109:1215–1221.
  7. Ketamine in the treatment of bronchospasm during mechanical ventilation Hemmingsen C, Nielsen PK, Odorico J. Am J Emerg Med. 1994;12:417–420.
  8. Negative results for ketamine use in severe acute bronchospasm: a randomised controlled trial Nedel WL, et al. Anaesthesiol Intensive Ther. 2020.

Crimson Circuit curiosities: original generated illustrations for Circulation Studio.

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