From the Research
Squatting increases right ventricular (RV) preload by enhancing venous return to the heart, as evidenced by the compression of lower extremity veins forcing blood toward the heart, increasing central venous pressure and right ventricular filling 1. When a person squats, the compression of lower extremity veins forces blood toward the heart, increasing central venous pressure and right ventricular filling. This position also increases peripheral vascular resistance by compressing arterial vessels in the legs, which further contributes to increased venous return. The increased RV preload results in greater right ventricular end-diastolic volume, leading to enhanced stroke volume through the Frank-Starling mechanism. This hemodynamic effect makes squatting a useful maneuver for patients with certain cardiac conditions like hypertrophic cardiomyopathy, as it can temporarily improve cardiac output. The increased preload also affects left ventricular function through ventricular interdependence, where greater right ventricular filling influences left ventricular geometry and function. Some key points to consider include:
- The effect of squatting on RV preload is immediate but temporary, lasting only while the squatting position is maintained, with hemodynamics returning to baseline upon standing 1.
- The importance of venous return in determining RV preload is highlighted by research on the mean systemic filling pressure, a key determinant of venous return 2.
- Treatment strategies for RV dysfunction, such as reducing wall stress and optimizing RV contraction, may be informed by the effects of squatting on RV preload 3.
- The relationship between RV preload and myocardial blood flow is complex, with elevated filling pressure potentially decreasing RV myocardial blood flow 4.
- Beta blockers, such as carvedilol or metoprolol XL, may be used to improve systemic RV function in patients with transposition of the great arteries and dysfunction of the systemic right ventricle 5.