Comparison of usefulness between exercise capacity and echocardiographic indexes of left ventricular function in cardiac amyloidosis

In patients with primary systemic amyloidosis (AL), the echocardiographic assessment of ventricular function alone does not always correspond to patients' symptoms and functional status. Peak oxygen uptake and anaerobic threshold (AT), in contrast, constitute 2 objective, reliable and reproducible indicators of functional status in patients with circulatory failure. Thirty-two consecutive patients (mean age 50 +/- 13 years) with histologic evidence of systemic primary AL were studied (29 AL, 3 hereditary). There were 16 with echocardiographic features of cardiac infiltration (group I) and 16 without (group II). Twenty age- and gender-matched healthy subjects were also studied for comparison. Of the 32 patients, 12 were in New York Heart Association functional class I, 9 were in class II, and 11 were in class III. Each subject underwent 2-dimensional and Doppler echocardiography and cardiopulmonary exercise testing using a modified Bruce protocol. Left atrial (LA), left ventricular (LV) dimensions, wall thickness, and LV fractional shortening, as well as transmitral flow velocities and their E/A ratio were measured. Peak oxygen consumption (VO2max [ml/kg/min]), AT (ml/kg/min), and exercise duration (seconds) were also measured. VO2max and AT were lower in patients with AL than in controls (20.8 +/- 7.0 vs 35.0 +/- 8.5, p <0.001 and 13.1 +/- 3.7 vs 27.0 +/- 4.2, p <0.001, respectively). As a group, symptomatic patients had lower VO2max, AT, and exercise duration than those without symptoms (17.1 +/- 3.6 vs 27.0 +/- 6.9, p = 0.0001, 11.1 +/- 2.1 vs 16.2 +/- 3.6, p = 0.0001, and 489 +/- 235 vs 843 +/- 197, p = 0.0001, respectively), whereas LV dimensions only showed a small difference (p = 0.03). VO2max, AT, and exercise duration of patients in functional class I were higher than those in functional classes II and III (p = 0.01, p <0.05, and p = 0.007, respectively). Asymptomatic patients had lower VO2max, AT, and exercise duration than controls (p <0.0001). VO2max, AT, and exercise duration were poorly related to LA diameter, LV dimensions, fractional shortening, wall thickness, peak velocities of E and A waveforms, and E/A ratio. Patients with VO2max > 15 ml/kg/min had a better survival than patients with VO2max < 15 ml/kg/min. Thus, in patients with primary systemic AL, cardiorespiratory exercise testing is the preferred way of assessing functional capacity. Echocardiographic Doppler indexes at rest are not predictive of a patient's symptoms and exercise capacity. Furthermore, VO2max is a strong independent predictor of survival in these patients.     

Pericarditis in infective endocarditis

Three patients with infective endocarditis who presented withsevere precordial pain and pericardial rubs are described inwhom sterile pericardial and pleural effusions were found. Thepericardial pain disappeared and the effusions regressed withsuccessful antibiotic treatment. A similar mechanism to thepostmyocardial infarction syndrome is suggested.     

Improved survival with amiodarone in patients with hypertrophic cardiomyopathy and ventricular tachycardia.

The effect of amiodarone on survival was assessed in patients with hypertrophic cardiomyopathy and ventricular tachycardia in a drug trial with historical controls. During 1976 and 1977, 24 hour (seven) or 48 hour (79) electrocardiographic monitoring was performed in 86 consecutive patients; 24 had ventricular tachycardia and received conventional antiarrhythmic agents. Nineteen clinical, echocardiographic, and haemodynamic features were assessed. Seven patients died suddenly during follow up of three years; of these, five had continued to have ventricular tachycardia and two had no documented ventricular tachycardia. During 1978 and 1979, ventricular tachycardia was detected during 48 hour electrocardiographic monitoring in 21 of the next 82 consecutive patients with hypertrophic cardiomyopathy. They received amiodarone (150-400 mg/day, median 300); ventricular tachycardia was suppressed in all during repeat 48 hour electrocardiographic examination. Two patients died suddenly during a three year follow up, but neither belonged to the amiodarone treated group with ventricular tachycardia. The clinical and haemodynamic variables were similar in patients taking amiodarone and conventional agents. The fact that control of ventricular arrhythmia with amiodarone is significantly associated with improved survival suggests that amiodarone may prevent sudden death in patients with hypertrophic cardiomyopathy and ventricular tachycardia.     

Light-dependent effects of a hydrolysis-resistant analog of GTP on rod photoresponses in the toad retina.

Responses to 100-ms flashes were recorded intracellularly from dark- and light-adapted rod photoreceptors in the isolated retina of the toad, Bufo marinus. Properties of photoresponses were analyzed under each condition of adaptation when retinas were superfused with 1.0 mM guanosine 5'-[beta, gamma-methylene]triphosphate (p[CH2]ppG), a hydrolysis-resistant analog od GTP. When applied to retinas that previously had been subjected to intense light (approximately 30% bleach), p[CH2]ppG increased both the amplitude and duration of photoresponses. By contrast, treatment of dark-adapted retinas with p[CH2]ppG did not alter these response parameters. When similarly applied to either dark- or light-adapted retinas, GTP had no effects on amplitude or duration of photoresponses. These results are discussed in terms of GTP-dependent mechanisms for rod adaptation.     

Pathways of influence on fifth and eighth graders' reports about having had sexual intercourse

The purposes of this study were to explore the differences between fifth and eighth graders' self-reports of having initiated sexual intercourse and the factors related to their early sexual debuts. The urban sample consisted of African American and white fifth (n = 59) and eighth (n = 169) graders. Among fifth graders 46% and among eighth graders 55% reported they had initiated sexual intercourse. Sexual intercourse was more common than other risk behaviors such as cigarette smoking and drinking. The multivariate analyses indicated that the influences on the early initiation of sexual intercourse were complex. Specifically, gender, use of alcohol, costs (i.e., perceptions of negative consequences), and personal norms (i.e., beliefs about when to initiate sexual intercourse) had no direct influence on having initiated sexual intercourse, but indirectly affected the initiation of sexual intercourse through the frequency of other intimate behaviors. The findings are discussed in terms of gender-specific socialization into sex roles and the need to design risk reduction interventions that incorporate messages from multiple social sources. © 1996 John Wiley & Sons, Inc.