Alcohol- and Caffeine-Induced Changes in Mitral Valve Echo Morphology and Auscultation in Healthy Females.

Mitral valve prolapse (MVP) is a common cardiac valve abnormality that affects women more frequently than men. We have shown that mild dehydration induces echocardiographic signs of MVP in healthy females more frequently than in males. The present study investigated whether ethanol and caffeine, two commonly used substances, will induce changes in mitral leaflet morphology in normal subjects and whether these changes are gender dependent. Ten healthy volunteers were examined after ingesting 0.95 g/kg ethanol at breath ethanol values of 0.025% +/- 0.005%, 0.050% +/- 0.005%, and 0.075% (peak) +/- 0.005%, and at decreasing ethanol levels of 0.050% +/- 0.005% and 0.025% +/- 0.005%. Twelve healthy subjects were studied at 1.5, 3, and 4.5 hours after ingesting 5 mg/kg body weight of caffeine in a randomized, double-blind, crossover manner. A significant increase in mitral valve shape index (MVSI) on apical four-chamber view was documented in females following ethanol ingestion at all ethanol levels. These changes were accompanied by auscultatory findings characteristic of MVP. Decreased systemic vascular resistance, and afterload and increased heart rate, also occurred after ethanol ingestion. A significant increase in MVSI occurred on parasternal long axis in females at peak caffeine level; auscultatory findings characteristic of MVP also were documented. MVSI increased slightly on apical four-chamber view in males; however, no male subject developed auscultatory MVP. Body mass index was significantly lower in females (20.8 +/- 0.7 kg/m(2)) versus males (23.7 +/- 0.3 kg/m(2), P < 0.05). All subjects lost weight after caffeine intake; afterload and contractility also were increased. This study documents that ethanol and caffeine, at concentrations similar to those present in social intake, induced significant echo changes in mitral leaflet morphology and auscultation suggestive of MVP in healthy females. These results suggest that in addition to apparent hydration state, recent ethanol or caffeine intake should be taken into consideration before making the diagnosis of MVP.