Joseph A. Diamond

Comparison of four echocardiographic techniques for measuring left ventricular ejection fraction

Accurate quantitative measurement of left ventricular (LV) ejection fraction (EF) by 2-dimensional echocardiography is limited by subjective visual endocardial border detection. Both harmonic and precision contrast microbubbles provide better delineation of endocardial borders than fundamental imaging. The aim of this study was to correlate 2-dimensional echocardiographic quantification of LVEF measured by 4 currently available techniques with radionuclide angiography. A total of 50 patients who underwent radionuclide (EF) measurement (47 of 50 had technically difficult echocardiograms by fundamental imaging) underwent echocardiography by 4 methods: fundamental alone, fundamental with contrast, harmonic alone, and harmonic with contrast. Three echocardiologists measured the biplane 2-dimensional echocardiographic LVEF independently and were blinded to radionuclide angiography. The correlation of echocardiographic EF with radionuclide EF improved incrementally with each method. However, contrast with harmonic imaging provided the closest correlation (r = 0.95, 0.96, and 0.95 as assessed by the 3 independent analysts.

Midwall fractional shortening is an independent predictor of left ventricular diastolic dysfunction in asymptomatic patients with systemic hypertension

Conventional measures of left ventricular (LV) systolic performance suggest that diastolic dysfunction precedes the development of systolic dysfunction in hypertension. Midwall fractional shortening is a new measure of systolic function that identifies hypertensive patients who have evidence of target-organ damage, impaired contractile reserve, and increased mortality. We therefore sought to determine whether depressed midwall fiber shortening is associated with abnormal diastolic function. Echocardiograms were obtained in 102 otherwise healthy hypertensive patients without treatment with normal conventional measures of systolic function. Of these, 15 had depressed midwall shortening based on previously described normative relations. Patients with depressed midwall shortening had slightly higher blood pressure. Abnormal diastolic function, defined as late (A) LV inflow velocity greater than early (E) velocity, was observed in 33% of those with normal midwall shortening but in 60% of those with depressed shortening (p <0.05). Patients with A/E >1 had lower absolute midwall fiber shortening (15 +/- 3% vs 18 +/- 3%, p <0.0001) but similar endocardial shortening. Patients with abnormal midwall shortening had higher A/E and longer isovolumic relaxation times (both p <0.05). In multivariate analysis, midwall fractional shortening, age, and heart rate were independent predictors (p <0.01) of A/E in a model including blood pressure, LV mass, and endocardial shortening. We conclude that subnormal midwall shortening predicts LV diastolic abnormalities in this population of hypertensive patients with otherwise normal measures of LV systolic function. Contrary to our previous understanding, depressed LV systolic performance, when identified with this newer method, occurs coincidentally with impaired diastolic function.

Niacin-induced myopathy.

Abstract Treating hypercholesterolemia is effective both for the prevention and regression of coronary artery disease. 1–3 Lipid-lowering agents are being used more frequently and practitioners are therefore more likely to encounter the unusual side effects of these drugs. Niacin (nicotinic acid, vitamin B3) inhibits very-low-density lipoprotein secretion by the liver. It lowers total cholesterol, low-density lipoprotein (LDL) and triglycerides and raises high-density lipoprotein (HDL). Treatment with niacin may reduce the incidence of nonfatal myocardial infarctions, and in conjunction with bile resins, promote regression of coronary lesions.1–3 It is the only lipid-lowering agent shown to reduce mortality,3 and has been given at lower doses to treat hypoalphalipoproteinemia (selective low levels of HDL). Niacin in conjunction with 3-hydroxy-3-methylglutaryl coenzyme A reductase inhibitors increases the risk of myopathy associated with the latter.2 We report here 2 cases of myopathy induced by niacin without concomitant treatment with other hypolipidemic agents and review the relevant literature.

Left ventricular midwall function improves with antihypertensive therapy and regression of left ventricular hypertrophy in patients with asymptomatic hypertension

Recent evidence suggests that regression of left ventricular hypertrophy (LVH) with antihypertensive therapy improves prognosis. The mechanism for this benefit is unknown but may be related to effects on myocardial performance. Midwall fractional shortening (mFS) is often depressed in patients with asymptomatic hypertension, is associated with LVH, and is a potent, independent predictor of outcome. We therefore examined whether antihypertensive therapy may improve midwall performance. mFS as well as conventional echocardiographic parameters were measured serially among 29 hypertensive persons during 6 months of drug therapy. Stress-adjusted and absolute midwall function improved by 10% and 11%, respectively (p <0.05), whereas no significant changes were detected in other measures of chamber function. Improvement in function was more pronounced in patients with concentrically remodeled ventricular geometry and in those who achieved greater reductions in left ventricular (LV) mass. Antihypertensive therapy and LV mass regression is associated with demonstrable improvements in cardiac performance when assessed using mFS. Determinations of mFS may have a promising role in identifying patients with early hypertensive heart disease, tracking responses to therapy, and in elucidating the potential beneficial effects associated with LV mass regression.

Effect of Long-term Eprosartan Versus Enalapril Antihypertensive Therapy on Left Ventricular Mass and Coronary Flow Reserve in Stage I-II Hypertension

SummaryA double-blind comparator study was performed in 528 hypertensive patients/baseline sitting diastolic blood pressure (SitDBP) 95–114mmHgl. The primary objective was to compare the incidence of drug-related cough in patients treated with enalapril and eprosartan. This paper reports the results of 27 asymptomatic patients who were recruited into a single centre substudy of the multicentre trial and randomised to receive either eprosartan (200–300u2009mg b.i.d.) or enalapril (5–20u2009mg o.d.). Blood pressure (BP) reduction, left ventricular (LV) mass regression and change in coronary flow reserve (CFR) after 6 months treatment with either eprosartan or enalapril were compared. At the end of the study, eprosartan and enalapril were found to have caused similar reductions in BP. There was an increase in CFR in the eprosartan group to 1.6 ± 0.3 and a decrease in CFR in the enalapril group to 1.3 ± 0.3. Neither value was significantly different from baseline although the difference between the two groups was si...

Ambulatory blood pressure monitoring and echocardiography—Noninvasive techniques for evaluation of the hypertensive patient

Clinic blood pressure measurements have only limited ability to determine which hypertensive patients are at greatest risk of cardiovascular events. Ambulatory blood pressure monitoring allows for noninvasive measurement of blood pressure throughout the 24-hour period. This may help to clarify discrepancies between blood pressure values obtained in and out of the clinic and confirm the presence of white-coat hypertension, broadly defined as an elevated clinic blood pressure but a normal ambulatory blood pressure. Ambulatory blood pressure values have been shown to have a better relationship to cardiovascular morbidity and mortality and end-organ damage than clinic blood pressure values. Further, patients with white-coat hypertension appear to be at greater risk of cardiovascular morbidity and end-organ damage than a normotensive population, although they are at less overall risk than a hypertensive population. Hypertensive heart disease is characterized by diastolic dysfunction, increased left ventricular mass, and coronary flow abnormalities. Left ventricular hypertrophy increases the risk of coronary heart disease, congestive heart failure, stroke, ventricular arrhythmias, and sudden death. A variety of invasive and noninvasive techniques are described herein that measure left ventricular mass, diastolic function, and coronary blood flow abnormalities. Most antihypertensive treatments promote regression of left ventricular hypertrophy and reversal of diastolic dysfunction, which may decrease symptoms of congestive heart failure and improve survival.

Comparison of two calcium blockers on hemodynamics, left ventricular mass, and coronary vasodilatory in advanced hypertension

Dihydropyridine and nondihydropyridine calcium channel blockers (CCB) differ in pharmacologic characteristics. Few clinical studies distinguish effects of CCB as monotherapy. We conducted a comprehensive comparison of two CCB on patients with moderate to severe hypertension. Thirty patients with pretreatment diastolic blood pressures > or = 100 mm Hg were randomly assigned to either nifedipine-GITS or verapamil-SR. Dose titration achieved a diastolic blood pressure of < or = 95 mm Hg or a decrease of > or = 15 mm Hg over 4 weeks. Clinic blood pressure (BP), 24-h ambulatory BP, exercise BP, left ventricular mass, systolic and diastolic function by echocardiography, and coronary flow reserve by split-dose thallium-201 imaging with adenosine were assessed at baseline, end of titration, 3 months and 6 months of treatment. Plasma renin activity, atrial natriuretic peptide, norepinephrine, and epinephrine were assayed. Both drugs caused similar reductions in clinic and 24-h ambulatory BP and similar reductions in left ventricular mass index. Compared to nifedipine-GITS, verapamil-SR produced a significantly lower resting and peak exercise heart rate. Nifedipine-GITS elicited a lower peak exercise systolic BP. At end titration nifedipine-GITS produced lower plasma atrial natriuretic peptide levels, no longer apparent by 6 months. Plasma norepinephrine was lower with verapamil-SR, also at end titration and at 3 months, but not at 6 months. Plasma epinephrine and plasma renin activity were unchanged by either drug. There was no difference for systolic or diastolic left ventricular function or coronary flow reserve between the two treatments. Once daily nifedipine-GITS and verapamil-SR are equally effective for reduction of arterial pressure in moderate to severe hypertension. Differences in their hemodynamic profiles and neurohormonal responses are consistent with preclinical pharmacologic characteristics. The clinical implications of their similarities and differences remain to be fully evaluated in outcome studies.

Normal or near normal myocardial perfusion stress imaging in patients with severe coronary artery disease.

Background Normal or near normal myocardial perfusion stress imaging (MPI) suggests the absence of life-threatening coronary artery disease (CAD). Nevertheless, there are instances where severe left main or three-vessel CAD may be present despite no significant perfusion abnormalities on MPI. Methods Review of Tl-201 or Tc-99m sestamibi MPI over a period of 5 years to ascertain the features that may prevent misdiagnosis. Out of 9171 tests, 3992 (44%) were interpreted as normal or near normal. For clinical reasons, 98 (2%) of these patients underwent coronary angiography within 6 months. Results A total of 3992 patients were interpreted as normal or near normal. Seventy (22 men/48 women; 58 ± 13 years) did not have obstructive CAD. Nine (six men/three women; 64 ± 8 years) had either left main (n = 3), three-vessel CAD with or without left main (n = 3) or severe proximal left anterior descending (n = 3) disease. Although both normal patients and patients with CAD had similar proportions of imaging artifacts, those with severe CAD had significantly more markers of CAD (increased lung Tl-201 uptake, transient ischemic cavity dilatation, stress-induced ST-segment depression, chest pain, and/or hypotension with exercise; P < 0.01; no CAD vs. severe CAD; two-tail Fishers Exact Test). Similarly, patients with moderate CAD by coronary angiography (n = 19), and a random sample of 250 patients (82 men/168 women; 62 ± 14 years) with normal or near normal MPI who did not undergo coronary angiography, had similar proportions of imaging artifacts but significantly fewer markers of CAD. Conclusion When dealing with individual patients, the referring physician and the interpreter of MPI studies should consider severe CAD when there are markers of CAD despite normal or near normal perfusion images.

Survival to the Age of 52 Years in a Man with Unrepaired Tetralogy of Fallot

Tetralogy of Fallot is the most common cyanotic congenital heart defect during infancy. It is composed of a ventricular septal defect, an overriding aorta, obstruction of right ventricular outflow, and right ventricular hypertrophy. Most patients experience cyanosis at birth and die in childhood without surgical intervention. The rate of survival at 40 years without surgical correction is only 3%. We present the case of a man with tetralogy of Fallot who survived until the age of 52 years without surgical intervention.

Comparison of Ambulatory Blood Pressure and Amounts of Left Ventricular Hypertrophy in Men Versus Women With Similar Levels of Hypertensive Clinic Blood Pressures

The purpose of this study was to assess several indexes of cardiovascular risk in men and women with moderate to severe hypertension. We found that women with moderate and severe hypertension have lower ambulatory blood pressure and less cardiac hypertrophy than men with similar clinic blood pressure.