During a cardiovascular clinical skills workshop, a group of medical students is reviewing the hemodynamic effects of various physical examination maneuvers on structural heart lesions. Match each described pathophysiological hemodynamic change (left) with the appropriate clinical scenario consisting of a bedside maneuver and its corresponding underlying cardiac pathology (right).
- Decreased left ventricular preload leads to reduced ventricular chamber size, resulting in earlier coaptation failure of the leaflets and moving the auscultatory click closer to .Strain phase of Valsalva in Mitral Valve Prolapse
- Increased systemic vascular resistance increases left ventricular afterload, which decreases the transvalvular forward pressure gradient and softens the associated crescendo-decrescendo murmur.Isometric handgrip in Severe Aortic Stenosis
- Abrupt reduction in venous return leads to a smaller left ventricular cavity size, which exacerbates systolic anterior motion of the anterior mitral leaflet and intensifies the murmur.Abrupt standing in Hypertrophic Cardiomyopathy
- Increased afterload impedes forward left ventricular stroke volume, thereby increasing the regurgitant fraction backward into the left atrium and intensifying the holosystolic murmur.Isometric handgrip in Mitral Regurgitation
- Decreased intrathoracic pressure augments venous return to the right heart, increasing right ventricular stroke volume and intensifying a holosystolic murmur at the lower left sternal border.Deep inspiration in Tricuspid Regurgitation
Answer
The correct matches align the precise alteration in preload or afterload caused by a maneuver with the corresponding physiological response of the structural valvular or myocardial defect.
Each pair correctly links a physiologic hemodynamic alteration to its corresponding clinical presentation. Isometric handgrip increases afterload, which worsens regurgitant murmurs (mitral regurgitation) by increasing backward flow, but softens forward flow murmurs (aortic stenosis) by reducing the transvalvular gradient. Preload reduction via the Valsalva maneuver or abrupt standing shrinks the left ventricle; this uniquely exacerbates the outflow obstruction in hypertrophic cardiomyopathy and causes earlier leaflet prolapse in mitral valve prolapse. Conversely, deep inspiration creates negative intrathoracic pressure that augments right-sided venous return, selectively intensifying tricuspid regurgitation.
Step-by-Step Solution
Key Concept
The physiologic basis of bedside cardiac maneuvers and their effects on ventricular volume (preload) and systemic vascular resistance (afterload) to differentiate structural heart murmurs.