European heart journal
-
European heart journal · Oct 1993
The link between acute haemodynamic adrenergic beta-blockade and long-term effects in patients with heart failure. A study on diastolic function, heart rate and myocardial metabolism following intravenous metoprolol.
The present study was performed to find possible mechanisms linking the early effects of beta-blockade with the observed long-term effects in patients with heart failure. In 57 patients with heart failure, 13 +/- 3.1 mg of metoprolol was given intravenously. The patients were investigated by invasive haemodynamics (n = 34), including collection of myocardial metabolic data during atrial pacing stress (n = 16), by radionuclide angiography during physiological atrial pacing (n = 13), and by a bedside evaluation (n = 10). ⋯ There was a trend towards an increase in myocardial lactate consumption after beta-blockade administration during atrial pacing stress. It is suggested that the surprisingly good tolerability seen after acute administration of beta-blockers to patients with severe heart failure may be explained by prolongation of the diastolic filling phase, which outweighs the negative inotropic effects. The reduced myocardial metabolic demand may allow the failing myocardium to recover and explain the excellent long-term effect on heart function following beta-blockade treatment.
-
European heart journal · Sep 1993
The arrhythmogenic substrate--diagnostic and therapeutic implications: hypertrophic cardiomyopathy.
Hypertropic cardiomyopathy provides an important model for the study of mechanisms of sudden death. Initiating factors for sudden cardiac death may include sinus tachycardia and paroxysmal supraventricular arrhythmias. The haemodynamic effects of such triggers may be modulated depending on the patients exercise haemodynamics, peripheral vasomotor control and autonomic function. ⋯ Attempts at individual risk stratification for sudden cardiac death using conventional risk factors and non-invasive techniques such as Holter monitoring identify a large group of patients, many of whom will not experience sudden cardiac death. Conventional electrophysiological methods such as programmed ventricular stimulation do not add to risk stratification inducing a variety of non-sustained or non-specific ventricular arrhythmias. A novel electrophysiological technique described in this article offers more promise in this regard.
-
European heart journal · Jul 1993
Randomized Controlled Trial Multicenter Study Comparative Study Clinical TrialA double-blind comparison of the long-term efficacy of a potassium channel opener and a calcium antagonist in stable angina pectoris.
The efficacies and safety of nicorandil, 20 mg b.d., and diltiazem, 60 mg t.d., in the treatment of stable angina pectoris were compared in a double-blind randomized parallel group study involving 123 patients. The duration of the study was 3 months. Exercise tolerance tests were performed by the patients when on placebo (day 0) and at the end of the study period (day 90). ⋯ Maximum exercise capacity, the amount of work that could be performed before reaching ischaemic threshold, and the amount of work required to reach onset of angina were significantly increased for both groups of patients on day 90 compared with day 0 (increase in maximum exercise capacity: nicorandil--6.9 +/- 18.9 kj, diltiazem--9.6 +/- 16.2 kj, P = 0.44 ns; increase in work to ischaemic threshold: nicorandil--9.4 +/- 18.1 kJ, diltiazem--14.7 +/- 15.4 kJ, P = 0.10 ns; increase in work to onset of angina: nicorandil--10.0 +/- 20.1 kJ, diltiazem--11.4 +/- 14.9 kJ, P = 0.68 ns). Differences between the two groups were not significant. The double product of systolic blood pressure x heart rate and peak exercise for both drugs was either unchanged or slightly decreased at ischaemic threshold.(ABSTRACT TRUNCATED AT 250 WORDS)
-
European heart journal · Jun 1993
Case ReportsDiagnosis of mitral valve myxoma by transesophageal echocardiography.
Mitral valve myxomas are rare. We report a patient with a mitral myxoma arising from the posterior mitral leaflet in whom transthoracic echocardiography revealed equivocal findings. However, transoesophageal echocardiography provided accurate relevant anatomical information including the size, morphological characteristics, and tumour attachment point.
-
European heart journal · Jun 1993
Comparative StudyMeasurement of cardiac output with the Quantascope, a novel Doppler device: comparison with thermodilution.
The Quantascope is a novel non-imaging echo-Doppler device designed to measure cardiac output. We have compared this device with thermodilution. ⋯ The cardiac output derived by the Doppler technique did not correlate with that derived by thermodilution (r = 0.36, P = NS). Compared with the currently accepted reference technique of thermodilution, we found measurement of cardiac output by the Quantascope to be inaccurate: this contradicts previous reports.