Serge Degré

Role of alpha-adrenergic coronary tone in exercise-induced angina pectoris

To provide more insight into the role of alpha-adrenergic coronary tone in exercise-induced angina, 9 patients with chronic stable angina underwent after coronary angiography a symptom-limited supine exercise test on a cyclo-ergometer. After recovery, phentolamine was directly injected into the most diseased vessel (2 mg in 5 minutes), and immediately thereafter the same exercise (identical workloads and exercise duration) was repeated. During exercise 1, heart rate (HR), mean blood pressure and cardiac index increased 51% (p less than 0.001), 23% (p less than 0.01) and 33% (p less than 0.01), respectively, and pulmonary artery wedge pressure (PA wedge) increased from 9 +/- 1 to 26 +/- 2 mm Hg (p less than 0.001). After intracoronary injection of phentolamine, control values (including PA wedge) at rest did not change significantly. During exercise 2, HR, mean blood pressure and cardiac index increased in a similar way--50% (p less than 0.001), 25% (p less than 0.01) and 40% (p less than 0.01), respectively; however the increase in PA wedge was less (p less than 0.01). ST-segment depression at the end of exercise 2 was smaller for identical workloads and double products: 1.5 +/- 0.3 mm vs 2.5 +/- 0.3 mm (p less than 0.01). ST/HR slope in exercise 2 also decreased 51% (p less than 0.01). These results show a less severe ischemic response after intracoronary alpha blockade and argue for an improvement in coronary blood supply.

Psychosocial and physical rehabilitation after heart transplantation: 1-year follow-up

Experience on the rehabilitation of 62 heart-transplanted patients with a mean follow-up period of 15 months and a total survival rate of 79% is reported. From the present study we may conclude that: (a) One month after surgery, oxygen consumption of transplanted patients compared to coronary artery bypass-grafted patients was statistically lower (p less than 0.025). An excess ventilation was observed in transplanted patients in relation mainly to an excessive increase in blood lactates. (b) Improvement of maximal working capacity observed immediately after grafting was still enhanced after 1 year of a comprehensive rehabilitation program (p less than 0.001). This improvement was more related with an improvement of the respiratory function and of the peripheral factors than with a circulatory effect. (c) Four months after transplantation 71% of the patients still at work 6 months before operation returned to work. (d) The quality of life, well-being and heart acceptation demonstrated an immediate increase in physical items after transplantation while psychosocial items decreased postoperatively and normalized after weeks or months.

Increased platelet aggregability and prostacyclin biosynthesis induced by intense physical exercise

Changes in platelet aggregability during maximal bicycle ergometry were studied in healthy untrained subjects. Ex vivo platelet aggregation in response to ADP and collagen was measured in whole blood by impedance aggregometry or by direct electronic counting in an Ultra-Flo 100 platelet counter. This last method revealed that the platelet aggregation induced by low concentration of ADP (0.5 - 1.0 microM) was significantly enhanced during exercise. The plasma level of beta-thromboglobulin and the urinary excretion of 2,3--dinor-6-keto prostaglandin F1 alpha were also increased. These data indicate that an intense physical exercise enhances the aggregability of human platelets and induces a compensatory increase in prostacyclin biosynthesis.

Effects of chronic congestive heart failure on 24-hour blood pressure and heart rate patterns: A hemodynamic approach

For 29 patients with congestive heart failure (CHF), 24-hour noninvasive ambulatory blood pressure (ABP) and heart rate (HR) measurement profiles were described, using the periodogram method, and were compared with the same findings in 22 matched controls. Right-sided heart catheterization was performed in all patients. The mean cardiac index was 2.2 L/min/m2 (range 1.3 to 2.9 L/min/m2). More severe CHF, as assessed by cardiac index, pulmonary artery wedge pressure, and right atrial pressure, correlated significantly with a reduction in the amplitude of the circadian ABP and HR rhythms (0.38 less than r less than 0.63; p less than 0.05). Moreover, a reduced increase in cardiac index during cycloergometric exercise in 11 CHF patients correlated with a blunting of the circadian systolic ABP and HR profiles (0.57 less than r less than 0.90; p less than 0.05). Our results indicate that there is a reduction in the amplitude of the circadian BP and HR rhythms related to the severity of CHF.

Calcium channel blockers cannot prevent pure vasospastic myocardial infarction.

Coronary artery spasm is a recognized cause of myocardial infarction. This report describes a case of myocardial infarction attributed to pure coronary spasm which was halted by a double perfusion with streptokinase and nitroglycerin. Further coronary artery spasm leading to a myocardial infarction could not be avoided several weeks later, although the patient was left on calcium channel blocker therapy. The two attacks were not preceded by warning angina pectoris, contrary to accepted belief. The best objective of end-point drug therapy and its assessment in vasospastic angina are discussed.

Does cardiac denervation affect the short-term blood pressure variability in humans?

Objective To explore the repercussion of cardiac denervation on the short-term blood pressure variability in humans, in order to assess the extent to which the variability of blood pressure is linked to the variability of heart rate. Methods Beat-to-beat blood pressure and RR interval time were recorded in 16 heart-transplanted patients and were compared with those of 10 healthy control subjects in the resting supine, sitting and standing positions. Blood pressure and RR interval variabilities were assessed by spectral analysis. Results The total blood pressure power and the supine and sitting very low-frequency, low-frequency and high-frequency blood pressure variability were similar in the heart-transplanted patients and in the controls, despite a marked reduction in the RR interval variability in the heart-transplanted patients. However, the heart-transplanted patients had lower standing low-frequency blood pressure variability than the control subjects. Moreover, very low-frequency and low-frequency RR interval variabilities reappeared in the long-term heart-transplanted patients but not in the short-term heart-transplanted patients (range of time after transplantation 53–124 and 3–25 months, respectively). Conclusions Short-term RR interval fluctuations are not mandatory for the maintenance of normal blood pressure variability in the supine and sitting positions, but may contribute to the increase in the low-frequency blood pressure variability which occurs normally in the standing position. Moreover, the long-term heart-transplanted patients had increased RR interval variability, which may have been caused by the reappearance of limited autonomic cardiac modulation. However, this increased RR interval variability did not affect the corresponding blood pressure variability.

Oral sustained-release nitroglycerin in chronic stable angina: A multicenter, double-blind, randomized crossover trial☆

Forty-six patients with stable angina pectoris were randomized to receive either oral sustained-release nitroglycerin (SRNG, 6.5 mg) or placebo (P) 3 times a day for a 2-week double-blind trial. They were investigated for the frequency of anginal episodes, for sublingual nitroglycerin consumption and for exercise tolerance. There was a slight but significant decrease in the number of anginal episodes (6.4 +/- 1.5 episodes/week with P, 4.9 +/- 1.7 with SRNG, p less than 0.005) and sublingual nitroglycerin consumption (3.9 +/- 1 tablets/week with P, 2.7 +/- 1 with SRNG, p less than 0.005). The patients performed 3 upright multistage (increments of 30 W every 3 minutes) exercise tests on a bicycle ergometer before the start of the study and 1 hour after the intake of SRNG or P, at the end of each double-blind phase. Exercise capacity, expressed as exercise duration, increased from 8.9 +/- 3.8 minutes with P to 10.2 +/- 3.8 minutes with SRNG (14.6%; p less than 0.001). At symptom-limited exercise, ST depression was significantly reduced (p less than 0.05) during the SRNG phase. Thirty-four patients (74%) reached a higher peak heart rate (139 beats/min with P, 145 beats/min with SRNG; p less than 0.001) and 35 patients (76%) a higher rate-pressure product (+6%; p less than 0.001). These changes in exercise tolerance are relatively modest and at least 11 patients would have benefited from larger doses of nitrates.(ABSTRACT TRUNCATED AT 250 WORDS)

Comparison of the Immediate Effects of Two Beta-Blocking Drugs: A Nonselective and a Cardioselective with Modest ISA in Exercise-Induced Angina

To compare the effects of two beta-blocking drugs: a nonselective (propranolol) and a cardioselective with modest intrinsic sympathomimetic activity (visacor), 24 patients with stable angina pectoris performed a control exercise (without medication) on a bicycle ergometer (increments of 30 W every 3 min), and thereafter were randomized to receive either propranolol (40 mg t.i.d.) or visacor (200 mg once daily) for a 48-hour double-blind trial. The 2 groups on control exercise were similar with regard to their exercise tolerance: 7.6 +/- 2.3 versus 7.1 +/- 1.4 min (NS) and the behavior of heart rate, systolic, diastolic blood pressure and double product, at rest and during exercise. They exercised on the 2nd day 2 h after the intake of propranolol or visacor. In the 12 patients randomized to propranolol, heart rate, systolic and diastolic pressures, double product were significantly reduced at rest, compared with control exercise: 67 +/- 8 versus 81 +/- 10 beats/min (p less than 0.01), 132 +/- 20 versus 146 +/- 21 mm Hg (p less than 0.02), 80 +/- 8 versus 88 +/- 10 mm Hg (p less than 0.02), 8,828 +/- 1,927 versus 11,863 +/- 2,138 mm Hg X min-1 (p less than 0.001), respectively. On the contrary, in the 12 patients randomized to visacor, these parameters at rest were less modified and only heart rate was significantly decreased: 71 +/- 9 versus 81 +/- 11 beats/min (p less than 0.05).(ABSTRACT TRUNCATED AT 250 WORDS)

Clinical and Hemodynamic Observations on Orally Administered Sulmazol (AR115BS) in Refractory Heart Failure

The acute effects of an oral preparation of sulmazol, a recently synthesized cardiotonic agent, were assessed by means of a Swan-Ganz catheter in 10 patients who had advanced heart failure that persis

Effect of oral sustained-release nitroglycerin on exercise capacity in angina pectoris: Dose-response relation and duration of action during double-blind crossover randomized acute therapy

Ten men with documented coronary artery disease and stable exertional angina underwent a double-blind crossover study to examine the benefit and the duration of action on their symptom-limited exercise capacity of 2 doses (2.5 and 6.5 mg) of sustained-release nitroglycerin (SRNG). A multistage bicycle test was performed in the sitting position by steps of 30 W each 3 minutes until the onset of typical angina pectoris. It was performed 24 hours before the start of the study; 1 and 5 hours after administration of placebo, and repeated after 2.5 and 6.5 mg of SRNG administered in a double-blind crossover study according to a 4 successive days protocol. No differences appeared between administration of placebo (1 and 5 hours) and the results obtained at the first exercise test. The dose of 2.5 mg of SRNG was effective on the symptom-limited working capacity but only at 1 hour (+9%; p less than 0.01). The dose of 6.5 mg was more effective both at 1 hour (+25%; p less than 0.001) and at 5 hours (+27%; p less than 0.001). All patients had angina at a higher heart rate (+5 to 8%; p = NS [not significant] and p less than 0.01), whereas systolic blood pressure and double product tended to be slightly but insignificantly increased. S-T depression at the onset of angina was insignificantly changed with placebo, and 2.5 and 6.5 mg of SRNG. It is concluded that 6.5 mg of orally administered SRNG is effective during at least 5 hours, and that the magnitude of the benefit and its duration are dose-related.