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Biomedical subjects

M Brignole

Publications and source records attributed to M Brignole.

At least 127 records · Page 7Linked to original sources
PubMed1985

[Cardioinhibitory reflex provoked by stimulation of carotid sinus in normal subjects and those with cardiovascular disease].

The normal range and the reproducibility of the cardioinhibitory carotid sinus reflex were studied in 288 apparently healthy subjects of different ages (aged from 17 to 84 yrs., 156 males, 132 females). In each subject we chose the longest RR interval as an activation index of the reflex obtained by carotid sinus massage; its mean value increased slightly with advancing age. In the were 1, 5, 2, 5, 3, 3 sec. respectively, with a 99% confidence limit. No sex difference was found. We studied also a group of 105 patients (aged from 39 to 82 yrs., 67 males, 38 females) with various types of cardiovascular disorders, without a previous history of spontaneous syncope. Abnormal maximum RR values were found in 18 of them (17%). This percentage was significantly higher than in normals (2%). In 11 patients (10%) the carotid sinus stimulation evoked a syncopal attack. It seems therefore that a statistically abnormal carotid sinus hypersensitivity can occur in a substantial number of cardiovascular patients without necessarily leading to spontaneous syncopal attacks. Finally the reproducibility of the cardioinhibitory reflex was tested in 42 patients with maximum RR interval values ranging from normal to extremely abnormal. In each subject a significant correlation (r = 0.79) was found between the maximum RR interval values tested in two occasions at intervals ranging from 1 hour to 3 months; besides a concordance in normal or abnormal result was present in 93% of the cases.

Adolescent↗
PubMed1985

[Association of the carotid sinus syndrome and orthostatic hypotension. Another potential cause of the failure of VVI electrostimulation].

The systolic blood pressure was measured during clinostatism and 15'', 1', 5' after standing in 101 patients with carotid sinus syndrome and in 101 controls matched for age, sex, and prevalence of organic heart disease. In the carotid sinus syndrome group we observed a greater systolic blood pressure reduction from the supine to standing position (20 +/- 19 vs 14 +/- 11 mmHg), a lower orthostatic pressure (111 +/- 23 vs 120 +/- 21 mmHg) and a greater incidence of orthostatic hypotension (defined as a blood pressure reduction greater than or equal to 50 mmHg or greater than or equal to 20 mmHg when orthostatic pressure was lower than 100 mmHg) (35% vs 17%). Twenty-three carotid sinus syndrome patients received a VVI pacemaker for control of their symptoms; after a mean follow-up of 12.2 +/- 7.7 months, unchanged or reduced symptoms persisted in 6 out 9 (67%) patients with previous orthostatic hypotension while only in 1 out of 14 (7%) patients without this feature. In conclusion, orthostatic hypotension is frequently associated with a carotid sinus syndrome and may account for relapses in some patients treated with VVI pacing.

Aged↗
PubMed1984

[Influence of beta block and autonomic nerve block on the recovery time of the sinus node in sick sinus syndrome and carotid sinus syndrome].

In order to evaluate the relative role of the automatic nervus system and of the intrinsic electrophysiologic properties on the sinus node function, we measured the corrected sinus node recovery time before and after autonomic nervous system blockade in 24 patients. Fourteen had a sick sinus syndrome, five had a carotid sinus syncope, two had syncope of unknown origin associated with bradycardia. Beta blockade was obtained by infusing metoprolol intravenously at a dosage of 0.2 mg/kg; complete automatic blockade was achieved by further i.v. administration of atropine at a dosage of 0.04 mg/kg. After beta blockade, the corrected sinus node recovery time increased in patients with sick sinus syndrome and intrinsic slow heart rate, whereas it decreased in patients with carotid sinus syncope or with syncope and bradycardia. In patients with sick sinus syndrome and normal intrinsic heart rate the response was variable. A positive direct correlation was found between the changes of the corrected sinus node recovery time induced by beta blockade and those induced by autonomic blockade; that is, both either prolonged or shortened the corrected sinus node recovery time. The changes of the corrected sinus node recovery time after beta blockade alone were inversely correlated with the intrinsic heart rate. We conclude that patients with intrinsic depression of the sinus node have an increased sympathetic tone.

Adult↗
PubMed1984

[Limitations of the stress test in the diagnosis of the sick sinus syndrome].

Exercise stress test in patients with sick sinus syndrome helps to evaluate the heart rate response to the increased sympathetic and to the decreased parasympathetic discharge. Aim of our study was the assessment of the diagnostic accuracy of exercise stress test in this condition. To do so, we measured the heart rate at peak stress in 18 patients with sick sinus syndrome (16 men and 2 women aged 51-78 years, mean 68). Two control groups were chosen: one of 14 healthy subjects of the same age and sex and a second one of 19 patients of the same age and sex, with comparable heart disease as the patients under study, but without sinus dysfunction. Heart rate at peak stress was expressed as percent of the expected maximal sex--and age--corrected heart rate (% max HR). The sick sinus syndrome group was characterized by the presence of: syncope and/or near-syncope in 10 patients; slight (2), moderate (9), severe (7) sinus bradycardia; corrected sinus node recovery time longer than 500 msec in 7 out of 15 patients, detected during an electrophysiological study; abnormal intrinsic heart rate in 5 out of 11 patients, obtained by means of drug-induced autonomic blockade (metoprolol 0,2 mg/Kg i.v. and atropine 0,04 mg/Kg i.v.), and evaluated according to Jose's equation; abnormal intrinsic corrected recovery time (greater than 450 msec) in 8 out of 11 patients; increase in heart rate after atropine infusion (0,02 mg/Kg i.v.) of less than 90 beats/min in 15 out of 18 patients.(ABSTRACT TRUNCATED AT 250 WORDS)

Aged↗
PubMed1983

[Role of body position during the carotid sinus stimulation test in the diagnosis of cardio-inhibitory carotid sinus syndrome].

The effect of body position during carotid sinus massage (CSM) for diagnosis of carotid sinus syndrome (CSS) of the cardioinhibitory type (CI) is not yet defined in the literature. The diagnosis of CSS-CI was made in 17 patients, the age range was 54 to 87 years (mean 74,7) on the basis of the following criteria: --history of recurrent syncope; --reproduction of symptoms during CSM repeated in different days in the presence of ventricular asystole that lasted more than 3 seconds; --absence of a vasodepressor reflex capable of producing symptoms, after a CI reflex was abolished by intravenous atropine; the blood pressure drop never exceeded 40 mmHg; --exclusion of other causes of syncope. In every patient the CSM was made in the supine position. If the test results were normal or left diagnostic doubts, the CSM was performed again in the standing position. Three different groups of patients were identified: a) normal result in the supine position, abnormal result in the standing position (cases 1 through 6); b) abnormal response both in the supine and in the standing position (7 and 8); c) abnormal response in the supine position, normal result in the standing position (9 and 10). In the cases 11 through 17 the CSM was not performed in the standing position because it was sufficiently diagnostic in the supine position. It is concluded that in the 35% of cases (6 of 17) the diagnosis of CSS-CI was obtained only after CSM was performed on the standing patient. In 53% of cases (9 of 17) the diagnosis was defined by CSM in supine position.(ABSTRACT TRUNCATED AT 250 WORDS)

Aged↗
PubMed1982

[Changes induced by temporary compression of A-V fistula on some polygraphic parameters in chronic hemodialysis patients].

In order to evaluate the influence of an arterio-venous fistula on cardiac function, a non-invasive study was conducted in thirty-three patients before and during compression of the fistula. Significant changes of PEP/LVET ratio and ITD were observed by means of such a technique only in patients with proximal (forearm) fistula; on the contrary no significant change were noted in those with distal (radiocephalic) a-v fistula. A systolic apical or precordial murmur, that was present in the control state in ten patients, was abolished or reduced in intensity in seven of them. Therefore suppression of blood flow through the shunt appears to affect the systolic time intervals in patients with proximal forearm fistula.

Adult↗