Hemodynamics & Heart Function Simulator : An interactive clinical heart function and hemodynamics simulator. Adjust heart rate, stroke volume, and blood pressure to visualize cardiovascular metrics and an active ECG in real time.
Hemodynamics & Heart Simulator
Manipulate physiological parameters in real-time. Witness synchronized chamber contractions, live clinical calculations, and an active ECG waveform tracer.
Clinical Controls
Hemodynamics Dashboard
Understanding Cardiac Mechanics & Hemodynamics
The cardiovascular system acts as a sophisticated, dynamic fluid circuit. The heart serves as a dual-pump engine generating flow, while systemic arteries provide resistive pathways that control the pressure supplied to tissues.
The Cardiac Cycle and the Wiggers Phenomenon
The mechanical action of the heart progresses through two primary phases: Systole (contraction and active blood ejection) and Diastole (relaxation and ventricles refilling).
During atrial diastole, passive venous blood flows from the vena cava and pulmonary veins into the Right Atrium (RA) and Left Atrium (LA). The electrical pacemaker, the **Sinoatrial (SA) Node**, initiates depolarization (seen as the **P wave** on an ECG), sending waves across the atria causing atrial contraction to finish ventricular filling.
Depolarization reaches the **Atrioventricular (AV) Node**, traveling down the Bundle of His and Purkinje fibers to trigger rapid, coordinated ventricular contraction (the **QRS complex**). Ventricular systole rapidly increases internal pressures, locking shut the tricuspid and mitral valves to prevent backflow, forcing open the aortic and pulmonary valves to expel blood.
Key Clinical Equations Explained
- Cardiac Output (CO) $$CO = \frac{\text{Heart Rate (HR)} \times \text{Stroke Volume (SV)}}{1000}$$ The absolute volume of blood delivered to the systemic circulation each minute. Normal resting range is roughly 4.0 to 8.0 L/min.
- Cardiac Index (CI) $$CI = \frac{CO}{\text{Body Surface Area (BSA)}}$$ Adjusts Cardiac Output for different body frames. Normal clinical values range from 2.5 to 4.2 L/min/m². Values below 2.0 indicate high cardiogenic hypoperfusion risk.
- Systemic Vascular Resistance (SVR) $$SVR = \frac{(MAP – CVP) \times 80}{CO}$$ Calculates total resistance presented by the arterial tree. Normal resistance is 800–1200 dynes·s/cm⁵. Elevated values point to systemic vasoconstriction, while low values indicate shock or systemic vasodilation.
Frequently Asked Questions (Cardiology Lab)
1. What is the significance of the Mean Arterial Pressure (MAP)?
2. How does physical training alter resting heart rate and stroke volume?
3. What goes wrong during cardiogenic shock?
4. What do different parts of the ECG wave trace signify?
- P Wave: Atrial depolarization, triggering atrial systole (contraction).
- QRS Complex: Massive electrical depolarization wave passing down ventricular walls, triggering ventricular systole. Atrial repolarization is buried inside this complex.
- T Wave: Ventricular repolarization, resetting myocytes for the next cycle (diastole).