ABSTRACTS

Comparison of Noninvasive and Invasive Measures of Left Ventricular Performance

RICHARD SUTTON, MB/WILLIAM P. HOOD, Jr., MD, FACC and ERNEST CRAIGE, MD, FACC Chapel Hill, North Carolina

Previous studies in laboratory animals and paCents under

controlled conditions have shown that the duration of

systolic time intervals correlates with certain measures

of left ventricular funct#ion. The present study compared

systolic time intervals, externally recorded in t,he routine clinical setting, with angiographic indexes of contractility.

Two groups were studied: 35 patients with normal left

ventricles (10 with normal diagnostic left hea.rt cathe- terization) and 21 paCents with failing left ventricles

(severe valvular or myocardial disease). From phono-

cardiograms, apex cardiograms and carotid arterial trac-

ings obtained in all patients, measurements were made of electromechanical interval, isometric contraction time and

pre-ejection period. Patients on digitalis had slightly shorter isometric cont,raction time and pre-ejection period,

and patients with left bundle branch block had slightly

longer electromechanical interval, but all 3 systolic time

intervals clearly separated failing from nonfailing ven-

tricles (P < 0.01). From serial biplane angiocardiograms

on 10 normal and all abnormal patients, left ventricular

ejection fraction and contractile element velocity at the

time of peak stress (V,,) were derived. Among t)he 31 pa- tienbs with catheteriza.tion data, correlation of pre-ejec-

tion period and isometric contraction time with ejection

fraction (T = -0.70) and with V,, (T = -0.60). The

electromechanical interval correlated less well with ejec- tion fraction (T = -0.58) and with V,, (T = -0.39)

This study indicates that of the external systolic time intervals recorded without rigidly controlled conditions,

pre-ejection period and isometric contraction time best

reflect left ventricular performance. We suggest that such

kxternal measurements may be used to follow progression of myocardial dysfunction without resorting to serial cardiac

catheterization.

Plasma Volume Measurements in Hypertension: Diagnostic and Therapeutic Implications

ROBERT C. TARAZI, MD, FACC/H. P. DUSTAN, MD EDWARD D. FROHLICH, MD, FACC and RAY W. GIFFORD, Jr., MD, FACC Cleveland, Ohio

Plasma volume determinations in 80 normal and 135 hyper-

tensive patients demonstrated significant differences among

various forms of hypertension; these differences were better

delineated by relating volume to diastolic pressure. Plasma volume was reduced in patients with essential

hypertension (72)) renovascular disease (28) and pheo-

chromocytoma (11) but not in renal parenchymal disease

(16) or primary aldosteronism (8). In contrast, with all

others, renal hypertension was alone associated with posi- tive volume/diastolic pressure correlation (T = 0.853 ; P < O.OOl), suggesting loss of adapt,ation to volume variations. A correlation study in men with essential hy- pertension allowed recognition of a subgroup with plasma

volume inappropriate for diastolic pressure: 30 hyper- tensive patients with diastolic pressure > 105 mm Hg

were clearly separable into 2 groups, 22 with contracted plasma volume (P < 0.001) and 8 with expanded volume

(P < 0.05). All 8 had diastolic pressures > 115 mm Hg,

Coronary Deaths Outside the Hospital

G6STA TIBBLIN, MD and LEIF LEHMAN, MD GBteborg, Sweden

Deaths from acute coronary heart disease occurring out- side the hmpital are now known to account for an im- portant proportion of t#he mortality from acute coronary heart disease. The reported proportion of a.11 deaths from

but became near normotensive with spironolactone and

thiazide; serum K was 3.9 vs. 4.2 for essential hypertension and 2.8 for prima.ry a.ldosteronism ; surgical exploration

in 2 showed no adrenal tumor. Plasma volume was not, expanded in the majority (6/8) of those wit,h primary

aldosteronism. There was no significant volume/diastolic

pressure correlation in t,hose with primary aldosteronism

or in the 8 “hypervolemic hypertensives”. Of the other

essentially hypertensive and renovascular hypertensive men and pheochromocytoma patients, all showed signif-

icant inverse volume/diastolic pressure correlations (P < 0.001 and < 0.05, respectively), so that, plasma volume was significantly reduced only in those with higher dia-

stolic blood pressures. Thus, in the absence of renal paren-

chymal disease, an inappropriately normal or expanded plasma volume despite high diastolic blood pressure would

suggest primary hyperaldosteronism or a form of hyper- tension responsive to spironolactone and diuretics.

coronary heart disease ranges from 42% in Framingham to 69% in Edinburgh. Little is known of the character- istics of t)hese patients or of the actual sequence of events

leading to death. A pilot study sponsored by the WHO Working Group

132 The American Journal of CARDIOLOGY