Rapid ventricular filling in left ventricular hypertrophy: I. Physiologic hypertrophy

Abstract

The effects of endurance training on the diastolic properties of the left ventricle were examined by comparing left ventricular filling rates in 11 male distance runners and 12 age-matched nonathletic control subjects selected to have nearly similar heart rates at rest. Maximal oxygen consumption was 69 +/- 11 ml/kg-min for the athletes and 48 +/- 8 ml/kg X min for the control subjects (p less than 0.001). Left ventricular end-diastolic dimension, posterior wall thickness and mass were determined by echocardiography, and average left ventricular filling rate was determined with a nonimaging scintillation probe. Electrocardiographic voltage was significantly greater in the athlete group than in the control group (sums of the voltages of the S wave in lead V1 and the R wave in lead V5 were 40 +/- 10 and 26 +/- 7 mV, respectively) (p less than 0.001), whereas ejection fraction was similar in the two groups. Despite a modest degree of left ventricular hypertrophy in the athlete group compared with the control group (left ventricular mass index 127 +/- 30 and 82 +/- 13 g/m2, respectively) (p less than 0.001), the average left ventricular filling rate was similar in the two groups (2.53 +/- 0.34 versus 2.38 +/- 0.29 end-diastolic counts/s, p = NS). There was no trend for the athletes with a higher left ventricular mass to exhibit a slower filling rate. These findings demonstrate that unlike pathologic hypertrophy associated with chronic hemodynamic over-loading, physiologic left ventricular hypertrophy is not accompanied by slowed left ventricular diastolic filling.

Favorable left ventricular remodeling following large myocardial infarction by exercise training. Effect on ventricular morphology and gene expression.

“…Ventricular function. In both endurance athletes and non athletic individuals, aerobic training induces physiologic ventricular hypertrophy which maintains normal wall stress and is not associated with impaired systolic and diastolic function ( 15,16). In heart failure exercise training protocols have uniformly improved peripheral metabolism and oxygen consumption yet there have been controversial effects on resting central hemodynamics with no direct measurements of contractility reported (24)(25)(26).…”

“…It is known that aerobic exercise training creates a physiologic form of hypertrophy in the myocardium without systolic or diastolic dysfunction (15)(16)(17)(18) or abnormal MHC gene expression in animal models (19). It follows that an intriguing possibility exists that suitably timed exercise training post myocardial infarction may overcome the abnormal fetal gene expression and morphological remodeling, and alter the natural course towards heart failure.…”

Effects of Coronary Blood Flow on Left Ventricular Function in Essential Hypertensive Patients.

“…These changes suggest that left ventricular hypertrophy associated with hypertension is not simply an adaptive process, but a pathological process. In fact, left ventricular hypertrophy in hypertension is accompanied by marked diastolic dysfunction, and in this regard it differs from left ventricular hypertrophy in athletes (30). The reactive and reparative fibrosis that occurs mainly with renin-angiotensin-aldosterone system activation seems to contribute much to left ventricular diastolic dysfunction (31).…”

The Athlete’s Heart

“…11,15,17,22,27,51 There was a significant difference with respect to interventricular septum thickness between control subjects and endurance-trained athletes (8.8 versus 10.5 mm, PϽ0.001) and between endurance-trained athletes and strength-trained athletes (10.5 versus 11.8 mm, Pϭ0.005) but not between endurance-trained athletes and combined endurance-trained and strength-trained athletes (Pϭ0.042).…”