This study examines the relation between left ventricular mass determined by two-dimensional echocardiography and exercise blood pressure in patients with hypertension. Sixty-seven patients with hypertension and 19 normal subjects underwent treadmill exercise testing and two-dimensional echocardiography. The left ventricular mass index in the normal subjects was 80 +/- 10 g/m2 (mean +/- SD). Patients with hypertension were classified into two groups according to left ventricular mass: Group I (n = 42) had normal mass and Group II (n = 25) had increased mass (greater than 2 SD above the mean value in 19 normal subjects). There was a poor correlation between left ventricular mass and blood pressure at rest. However, a better correlation was found between left ventricular mass and exercise systolic blood pressure (r = 0.58, p less than 0.001) or the change in systolic blood pressure from rest to exercise (r = 0.48, p less than 0.001). Twenty-two (76%) of 29 patients with an exercise systolic blood pressure of 190 mm Hg or greater had an increased left ventricular mass index, whereas only 3 (8%) of 38 patients with an exercise systolic blood pressure of less than 190 mm Hg had an increased left ventricular mass index (p less than 0.0001). Thus, in patients with hypertension, left ventricular mass index is poorly related to blood pressure at rest, but is related to exercise systolic blood pressure. Patients with an exercise systolic blood pressure of 190 mm Hg or greater usually have an increased left ventricular mass. These findings may have therapeutic implications.

SUMMARY We have simplified the Gorlin formula and have compared our measurements of the aortic or mitral valve area, using the original Gorlin formula and the simplified valve formula in 100 consecutive patients. The valve area was measured by the simplified formula as cardiac output (I/min) divided by the square root of pressure differences across the valve.In patients with aortic stenosis of varying severity there was excellent correlation between the original One of the constants is the discharge coefficient that is an empirical constant with an assumed arbitrary value of 1 for the aortic valve and 0.7 for the mitral valve. The second constant is 44.5, which is equal to the square root of twice the gravity acceleration factor (980 cm/sec/sec). The flow across the valve is equal to the cardiac output (ml/min) divided by the product of the heart rate (beats/min) and the systolic ejection period or diastolic filling period (sec/beat). In 1972, Cohen and Gorlin revised the original formula and suggested the use of 0.85 for the mitral valve (instead of 0.7) as the discharge coefficient.2Because the original formula is cumbersome and time-consuming, it is rarely used by cardiologists who are not involved with hemodynamic measurements. We have simplified this formula, and our results by both the original and the simplified formulas in 100 patients with either aortic stenosis or mitral stenosis are the subject of this report. of the ejection to the dicrotic notch. The diastolic filling period was measured between the crossover points of the pulmonary artery wedge and the left ventricular pressure tracings. The heart rate was calculated at the time of cardiac output measurement by counting the RR cycles over a 60-second interval. The peak aortic gradient was measured as a simple peak-topeak gradient. The peaks were not necessarily at the exact time during systole. The mean pressure difference across the aortic or mitral valve was measured by planimetry. We used the same cardiac output in both the original Gorlin and the simplified formulas.The aortic or mitral valve area (cm2) was measured by the simplified formula as the cardiac output (1/min) divided by the square root of the pressure differences across the valve. For the aortic valve, we used either the peak or the mean pressure difference across the valve in the simplified formula, but for the mitral valve, we used only the mean pressure difference.We performed the statistical correlation by means of Pearson product moment correlation and the t test.

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