Induction of the diving reflex, by immersion of the face in cold water (2 degrees C) while the breath was held, converted paroxysmal atrial tachycardia to sinus rhythm within 15-35 seconds in seven patients (aged 22-66). Four had histories of heart attacks that had previously required vasopressor therapy, and two had been digitalised; three had no history of prior paroxysmal atrial tachycardia or heart-disease.
Failure of the pacemaker is a common complication of pacemaker therapy. Identification of the disorder responsible for the failure to pace is often difficult. An increase in myocardial threshold can result in nonconduction of the artificial impulse, particularly near the end of the life of the battery, when the output of current has started to decline. This report demonstrates such an increase in myocardial resistance which was apparent only upon massage of the carotid sinus.
Lithium salts have been widely used for several years in the treatment of manic-depressive psychosis. Various side-effects of lithium salts have been described. The present case report present two patients in whom sinus node dysfunction leading to syncope was caused by lithium. One of the cases showed signs of depressed sinus node function even when not on lithium, but no symptoms arose until lithium treatment was commenced. The second case showed no signs of depressed sinus node function when lithium was withdrawn.
We investigated 76 patients with carotid sinus syndrome followed over a time period of 12-40 months (mean 24 months). In 27 patients long-term ECG were recorded over 24 hours continuously. Carotid Doppler sonography was performed in all patients. 14 patients were studied electrophysiologically. The long-term ECG examinations in patients with carotid sinus syndrome showed a significant tendency to nocturnal bradycardia, and normal heart frequency during the day. In 41% of patients extracranial obstruction of internal carotid arteries could be demonstrated.
A prospective study examined the diagnostic yield and therapeutic efficacy of electrophysiologic studies in patients with SUO. We defined SUO as those syncopal or near-syncopal events remaining unexplained after a standardized, noninvasive evaluation that included a history, physical examination, routine laboratory screening, EEG, nuclear brain scan or CAT scan, 12-lead ECG, chest x-ray, orthostatic vital signs, bedside carotid sinus massage, and at least 24 hours of continuous ECG monitoring.
Because syncope may occur intermittently in patients with carotid sinus hypersensitivity, a knowledge of its natural history is needed as a basis for interpreting the usefulness of therapy. Fifty-six consecutive patients are described (47 men and 9 women; mean age 61 years) with carotid sinus hypersensitivity and syncope in whom 24 hour ambulatory monitoring and intracardiac electrophysiologic study revealed no other cause for the syncope. The mean duration of symptoms was 44 months (range 1 to 480) and the mean number of episodes was 4.0 (range 1 to 20).
In a 64-year-old male, recurrent syncope, hypotension and bradycardia developed repeatedly. The systolic blood pressure fell and could not be measured by auscultation method and the heart rate decreased to under 20 bpm. He recovered from unconsciousness in several minutes. No precipitating cause was apparent for such episodes. Physical examination revealed swollen lymph nodes in the upper cervical regions. Carotid sinus massage caused a fall of systolic blood pressure by 40 mmHg and the P-P interval lengthened to 1.96 sec. The otolaryngeal examination showed neoplasma in the pharynx.
The aim of the study was to evaluate the importance of atrial synchronism for pacing therapy of patients with mixed carotid sinus syndrome. On 23 patients (21 m, 2 f; mean age 69 +/- 8 years) affected by symptomatic mixed carotid sinus syndrome we performed: 1) the study of ventriculo-atrial conduction, 2) the evaluation of pacemaker effect and 3) the carotid sinus massage in standing position during VVI and DVI temporary pacing. All patients received a permanent DVI pacemaker and then underwent a two-month period single-blind, randomized, cross-over study on DVI vs VVI mode.
The aim of this study was to evaluate the importance of atrial synchronism for pacing therapy of patients with mixed carotid sinus syndrome. In 23 patients (21 m, two f; mean age 69 +/- 8 years) affected by symptomatic mixed carotid sinus syndrome we performed: (1) Research of ventriculo-atrial conduction, orthostatic hypotension and pacemaker effect; and (2) Carotid sinus massage in the standing position during VVI and DVI temporary pacing.
131 patients received permanent pacemakers to treat their hypersensitive carotis sinus syndrome (HCSS). Prior to implantation, HCSS was diagnosed whenever spontaneous episodes of faintness or dizziness (n = 25) or syncope (n = 106) coincided with an abnormal response to carotis sinus massage (asystole greater than 3 s). 123 patients were followed for 48 +/- 27 months after implantation to assess the value of pacemaker therapy. 77% of all patients were free of initial symptoms. 90% of patients with syncope prior to pacemaker therapy were free of recurrence.