SYNOPSIS
To investigate autonomic nervous system involvement in cluster headache (CH) and migraine, we compared the cardiovascular reflex responses of common migraine and CH subjects to a group of controls. A battery of 5 well‐codified autonomic tests was applied: (1) deep breathing test (DB); (2) lying to standing test (LS); (3) Valsalva manoeuvre (VAL); (4) postural hypotension test (PH); (5) blood pressure response to sustained handgrip (SHG). Our data confirm an autonomic dysfunction in CH, mainly affecting the parasympathetic system. Evidence for an impairment of sympathetic cardiovascular reflex regulation was obtained in the common migraine group.
In 20 runners the intra-arterial blood pressure changes determined by a long-distance run and by a maximal bicycle ergometric test were recorded by means of the portable Oxford system. A peculiar pattern of the phasic waves was observed throughout the run: continuous rhythmic pulse pressure oscillations ranging in frequency between 4 and 28/min and unrelated to respiration were detected. The shape of these oscillations prompted us to investigate whether they were due to a "beat" phenomenon, that is, to the combined effect of two waves with a nearly equal frequency. To test this hypothesis, during the run 10 athletes carried a fluid-filled container around the chest. The pressure waves recorded in the container were added by computer to those recorded intra-arterially during bicycle ergometry. The resultant harmonic showed a pattern similar to that recorded in the athlete's radial artery during running. Conversely, by subtracting the pressure waves recorded in the container from those simultaneously recorded at the radial artery during running, nearly flat tracings were obtained. The source of the beat phenomenon has therefore been identified in the wave, which generates inside the aorta and the great vessels at each foot-strike shock.
In 30 highly trained boys aged 10-14 the prevalence of ventricular ectopic beats and Q-T interval duration were studied. In trained boys ECG Holter monitoring showed a higher even though not significantly different prevalence of ventricular arrhythmias than in 30 age-matched untrained controls. Ventricular ectopy was on the contrary lower than in a group of 30 adult athletes. Q-T corrected (Q-Tc) interval in the trained boys was longer than in the sedentary controls (p < 0.001), while it was as long as in the adult athletes. No correlation was found between the degree of severity of ventricular ectopic beats and Q-Tc interval duration, heart rate or echocardiographic dimensional and functional findings. The clinical and prognostic importance of complex ventricular arrhythmias detected in healthy athletes remains to be elucidated.
Exercise training is currently recommended in the management of mild hypertension, but the relationship between training and ventricular arrhythmias has never been investigated in hypertensive subjects. Forty hypertensive sportsmen were studied by means of 24-h ECG Holter monitoring and the results were compared with those obtained in 40 sedentary hypertensives, 40 normotensive sportsmen and 40 normotensive sedentary subjects. Among the hypertensive sportsmen 82.5% exhibited at least one ventricular extrasystole and 32.5% complex forms of ectopy, a prevalence higher than that observed in the sedentary hypertensives (50% and 17.5%; P = 0.002). In the normotensive sportsmen the prevalence of ventricular arrhythmias (62.5% and 22.5%) was lower than that in the hypertensive sportsmen, but the difference was not statistically significant. During a training session the prevalence of ventricular ectopy was similar in the two groups of trained individuals. Among the hypertensive sportsmen no correlation was found between the severity of ventricular arrhythmias and the degree of left ventricular hypertrophy and performance. The results of the present study suggest that exercise training may enhance left ventricular vulnerability in hypertensive subjects. Whether subjects who manifest complex ventricular arrhythmias should continue to train remains a matter for individual judgement.
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