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TABULAR DATA OMITTED Cardiovascular and peripheral adaptations to an aerobic conditioning program were studied in 30 hypertensive adults taking either Placebo',[beta][.sub.1]-selective [beta]-adrenergic blocker (metoprdol) or [beta][.sub.1]-nonselective [beta]-adrenergic blocker (propranoid). The placebo group increased aerobic capacity (V0[.sub.2]max) 24% (p (Am J Cardiol 1990;66:591-596), Beta-adrenergic blocking agents prevent the activation of beta-adrenergic receptors, which are specialized cell membrane proteins that trigger specific cell processes such as heart rate and contraction. However, these drugs have been shown to decrease the capacity for exercise and to diminish conditioning response to aerobic exercise in healthy individuals. Studies have also shown that exercise conditioning normally increases aerobic capacity and decreases resting blood pressure in patients with high blood pressure (hypertension). Although beta-adrenergic blocking agents are commonly used to treat hypertension, the effects of these drugs on exercise conditioning in hypertensive patients are not known. However, a drug that selectively blocks the beta-1-type receptors may not affect the beta-2 receptor-mediated dilation of blood vessels during exercise. Hence, the effects of the beta-1 receptor blocking agent metoprolol and the nonspecific beta receptor blocker propranolol on exercise conditioning response were assessed in 30 patients with hypertension. Aerobic conditioning resulted in a 24 percent increase in aerobic capacity, reduced blood pressure, and decreased systemic resistance (the force against which blood flows in the peripheral circulation), in patients who were not treated with beta blocking agents. Aerobic capacity was increased by 8 percent and blood pressure decreased in patients treated with metoprolol. Patients treated with propranolol had no increase in aerobic capacity, no reduction in blood pressure, and no adaptation of the heart and blood vessels to exercise training. These findings show that selective beta-1 blocking agents such as metoprolol and nonspecific beta blocking agents such as propranolol can diminish the exercise conditioning effects in hypertensive patients to varying degrees. (Consumer Summary produced by Reliance Medical Information, Inc.)

This report presents a case of an unusually large unruptured sinus of Valsalva aneurysm complicated by right ventricular outflow tract obstruction, right coronary artery occlusion and incomplete right bundle branch block. Two-dimensional and Doppler echocardiography were instrumental in preoperative diagnosis and postoperative follow-up.

Incomplete closure of the tricuspid valve without apparent cusp disease was noted on two-dimensional echocardiography in 31 patients. This abnormality was defined as a failure of the tricuspid valve leaflet tips to reach the plane of the tricuspid valve anulus by at least 1 cm in the standard apical four chamber view at the point of maximal systolic closure. This resulted in a final systolic leaflet position deeper within the right ventricular cavity than is normally seen. The finding was present in the following diagnostic subgroups: Group A, pulmonary hypertension (11 patients); Group B, rheumatic heart disease (4 patients); Group C, dilated cardiomyopathy (9 patients) and Group D, previous myocardial infarction (7 patients). Right atrial, right ventricular and tricuspid anulus measurements were made and compared with those from a group of 67 normal subjects. The results were as follows: right atrial endsystolic area = 27.2 ± 8.6 cm2 (normal = 13.4 ± 2.0); right ventricular end-systolic area = 25.6 ± 8.7 cm2 (normal = 10.9 ± 2.9); right ventricular end-diastolic area = 31.5 ± 9.1 cm2 (normal = 20.1 ± 4.9) and tricuspid valve anular end-systolic dimension = 4.0 ± 0.6 cm (normal = 2.2 ± 0.3). The differences from the normal data were all statistically significant (p < 0.001).

A new technique for quantitatively mapping the three-dimensional left ventricular endocardial surface was developed, using measurements from standard cross-sectional echocardiographic images. To validate the accuracy of this echocardiographic mapping technique in an animal model, the endocardial areas of 15 excised canine ventricles were calculated using measurements made from echocardiographic studies of the hearts and compared with areas determined with latex casts of the same ventricles. Close correlation (r = 0.87, p < 0.001) between these two measures of endocardial area provided preliminary confirmation of the accuracy of the maps.

• A kindred with a high incidence of hypertrophic cardiomyopathy (HC) was studied to identify the presence of clinical hyperthyroidism. Two and possibly three members with HC had associated hyperthyroidism. In the propositus, clinical, ECG, and vectorcardiographic evidence for HC resolved after treatment of the hyperthyroidism. We hypothesize that the disproportionately high correlation of hyperthyroidism and HC and the resolution found in the propositus after treatment may indicate that antithyroid therapy should be considered in this form of cardiomyopathy.(Arch Intern Med 1983;143:378-380)

A 69-year-old woman experienced recurrent presyncope during a two-week period. Six years previously, a total abdominal hysterectomy with preoperative radium implantation had been performed for stage II uterine carcinoma. The patient was an obese woman who was slightly dyspneic at rest. Her BP was 94/70 mm Hg, her pulse rate was 80 beats per minute, and her respirations were 24/min. The examination findings were otherwise unremarkable. A 12-lead ECG showed sinus rhythm (rate, 80 beats per minute) with a right bundle-branch block. A chest roentgenogram was normal. A technetium Tc 99m albumin aggregated perfusion scan of the lungs demonstrated several bilateral lobar and segmental defects; therapy with intravenous heparin was begun. During the ensuing days, hypotension and episodic cyanosis occurred. On the third hospital day, cross-sectional echocardiography was performed (Fig 1).What is your diagnosis? DIAGNOSIS.—RIGHT ATRIAL THROMBUS. The cross-sectional echocardiogram shows dilated right-sided cardiac chambers. An irregular,

Competition experiments between Escherichia coli mutT1and mut+populations show that the mutator gene confers selective advantage on the strain that carries it. The observed increase in fitness varies, with an average increase in mutator growth rate of 1.4 percent when mutator and wild-type strains are grown together in chemostats.