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Query: UMLS:C0018799 (heart disease)
 34,133 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

To clarify the clinical significance of an abnormally prolonged paced QRS duration, we studied 114 patients who had undergone pacing for atrioventricular block (AVB). Patients were divided into two groups: group I consisted of 29 patients with at least one paced QRS duration greater than or equal to 180 msec during the follow-up period; group II consisted of 85 patients with paced QRS durations less than 180 msec. The clinical background, QRS complexes before pacing, and the echocardiographic findings were assessed. Males (P less than 0.05), those with H-V block (P less than 0.05) and a wider QRS complex of conducted and escape beats (both P less than 0.01) were dominant in group I. The incidence of underlying heart disease was greater in group I than in group II (83% vs 32%, P less than 0.01). Reduced left ventricular ejection fraction (LVEF) and increased left ventricular end-diastolic dimension (LVDd) were more prominent in group I than in group II (LVEF 0.49 +/- 0.17 vs 0.68 +/- 0.10, P less than 0.01, LVDd 57.1 +/- 7.9 mm vs 48.5 +/- 5.6 mm, P less than 0.01). The paced QRS duration correlated with LVEF (r = -0.61) and LVDd (r = 0.81). A paced QRS duration greater than or equal to 180 msec was sensitive and specific for a LVEF less than 0.5 (83.3% and 85.2%) and LVDd greater than or equal to 60 mm (100% and 81.4%). We conclude that patients with a prolonged paced QRS duration have more serious heart disease, and the paced QRS duration can be a useful indicator of impaired LV function.
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PMID:Clinical significance of QRS duration during ventricular pacing. 137 97

The arrhythmias in competitive athletes may be classified as "benign," "paraphysiological" due to prolonged athletic training, or "pathological" due to hemodynamic effects on the athletic performance-risk-arrhythmogenic substratum. Pathological arrhythmias include life-threatening forms that are severe enough to produce symptoms (presyncope, syncope, cardiac arrest) during athletic activity. These forms are in particular rapid VT, VF, torsades de pointes, preexcited atrial fibrillation, sinus atrial and AV block. Our study population includes 766 competitive athletes, mean age 21.1 years (74 top international level), investigated with a cardioarrhythmological work-up for symptoms and for arrhythmias from 1974 to June 30, 1991. Three leading categories, represented by 16 aborted sudden death, 8 sudden death, and 7 induced VF (by EES or TAP) athletes, are described. All athletes with life-threatening arrhythmias, previously as asymptomatic or with minor symptoms had an arrhythmogenic substratum due to underlying silent cardiopathy or primary arrhythmic disorders. Athletic activity can be regarded as a trigger of electrical destabilization.
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PMID:Life-threatening tachyarrhythmias in athletes. 138 4

Doppler-echocardiography is playing an increasing role in cardiac pacing: 1) Before implantation, to determine any cardiac disease possibly accompanying the conduction disturbance, and the quality of atrial function in order to identify the appropriate indications for the type of pacing which will restore normal AV synchronism. Alongside morphometric data (size of atria, etc.), this analysis is based above all on the evaluation of LV filling flows and ejection, if necessary during provisional pacing in DRV mode. It is important to be aware of and prevent certain problems: 1st degree AV block with very long PR, high degree interatrial conduction disturbances, etc. 2) To evaluate the possible benefits of pacing in certain new indications, e.g. obstructive hypertrophic cardiomyopathy (measurement of intra-LV gradient in sinus rhythm and with DRV pacing with total ventricular capture). 3) After implantation, to optimise the programming of double-chamber pacemakers and in particular AV intervals (base-line AV interval with paced atrial cycle, AV interval with detected atrial cycle, hysteresis of AV interval corresponding to the difference between the two previous values, slope of automatic variation in AV interval during exercise, etc.). Individual programming of these parameters based upon analysis of transmitral and ejection flow rates, at rest and, if necessary, during exercise, enables the optimisation of cardiac function (which is above all useful in the presence of concomitant organic heart disease) while at the same time improving the electrophysiological behaviour of the pacemaker at high frequencies.
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PMID:[Doppler echocardiography and double chamber pacing]. 141 72

Atrioventricular block I has a benign natural course, and permanent pacing is not warranted. Second-degree AV block, including both type I and type II, can have an ominous course, especially in older patients with underlying heart disease. One study claims that the prognosis in patients with second-degree AV block, irrespective of type, is improved by permanent pacing. In spite of lack of controlled studies it has been convincingly shown that VVI pacing prolongs life in patients with high-grade AV block. Two studies suggest that atrial synchronous pacing in patients with congestive heart failure and high-grade AV block might improve their survival. Studies comparing survival with different pacing modes in patients with sinus node disease support the hypothesis that physiologic pacing can improve survival. Prophylactic pacemaker implantation even in symptomatic patients with chronic bifascicular block does not seem to protect them from sudden death.
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PMID:Survival in patients with permanent pacemakers. 142 81

The case is reported of a 20-month-old girl admitted to our centre for group B streptococcal endocarditis who died of complete atrioventricular block after a week of treatment. There was no history pointing to the presence of a heart disorder. Necropsy disclosed the surprising existence of a vast rheumatic carditis involving essentially the aortic and mitral valves, with bacterial superinfection of the former. The double rheumatic and infectious lesion in such a young patient with infective pseudo-aneurysms of the sinuses of Valsalva makes this an exceptional case.
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PMID:Unsuspected rheumatic heart underlying group B streptococcal endocarditis at the age of 20 months. 142 95

The ECG is useful in diagnosing acute myocardial infarction and unrecognized Q-wave myocardial infarction in the elderly. Unrecognized myocardial infarction and myocardial infarction associated with clinical symptoms have a similar incidence of new coronary events. Ischemic ST-segment depression on the resting ECG is associated with an increased incidence of new coronary events. The ECG is useful in the diagnosis of LV hypertrophy but is less sensitive and less specific than echocardiography in diagnosing LV hypertrophy. ECG LV hypertrophy is associated with an increased incidence of cardiovascular events in the elderly. However, echocardiographic LV hypertrophy is more sensitive in predicting new coronary events, atherothrombotic brain infarction, and congestive heart failure than is ECG LV hypertrophy. The ECG is also useful in diagnosing conduction defects and arrhythmias in the elderly. In the elderly, left bundle branch block, intraventricular conduction defect, Type II second-degree atrioventricular block, and pacer rhythm are associated with an increased incidence of new cardiac events, whereas right bundle branch block, left anterior fascicular block, and first-degree atrioventricular block are not. In the elderly, atrial fibrillation is associated with an increased incidence of thromboembolic stroke and new cardiac events. Premature atrial complexes and paroxysmal supraventricular tachycardia are not associated with an increased cardiac risk. Complex ventricular arrhythmias on the resting ECG are associated with an increased incidence of cardiac events in elderly patients with heart disease but not in elderly patients without heart disease.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Usefulness of the resting electrocardiogram in the elderly. 147 52

Seven out of 829 pediatric cardiac patients (0.84%) were found to have sinus node dysfunction (SND) over the past seven years. Of the seven patients, three had structurally normal hearts. One of these three patients had long QT syndrome. In four patients, structural heart disease was noted. In three of these four patients the sinus node dysfunction was attributed to cardiac surgery. The age of onset of SND ranged from four months to eight years. Presenting symptoms and signs included syncope, near-syncope, seizure and congestive heart failure. Two patients were asymptomatic. Five patients had episodic sinus pause. Sinus or junctional bradycardia was noted in four patients. Three had tachy-bradycardia. High grade atrioventricular block was noted in one patient. Treadmill exercise test revealed a nonsustained ventricular tachycardia in two patients. All seven patients were found to have prolonged maximal corrected sinus node recovery time. Prolonged intra-atrial conduction time was found in three, prolonged AV nodal conduction time in one, and prolonged His-Purkinje conduction time in one patient during the electrophysiologic study. All seven patients showed abnormal results in intrinsic heart rate study. Anti-arrhythmic drugs were prescribed. During the follow-up study, no patient died, but two patients received a pacemaker implantation. Because of the extent of their conduction system diseases, it is recommended that patients with SND should be thoroughly investigated.
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PMID:Sinus node dysfunction in children. 151 8

Catheter ablation of the atrioventricular node is a therapeutic technique for the treatment of patients with drug-refractory supraventricular tachyarrhythmias. In our Arrhythmia Unit 25 patients (8 women, 17 men) aged (mean +/- DE) 56 +/- 10 years have undergone fulguration of the atrioventricular junction since 1986. The more frequent treated rhythm disturbance was atrial flutter or fibrillation, with uncontrolled rapid ventricular response. Absence of organic heart disease was diagnosed in 9 patients; the remainder had valvular heart disease (2), cor pulmonale (2), cardiomyopathy (7), hypertensive heart disease (2) and Wolff-Parkinson-White syndrome (3). Under general anesthesia 1.8 +/- 0.8 shocks/patients were delivered along 1.2 +/- 0.7 sessions/patient. In 23 of 25 patients (92%) complete atrioventricular block was achieved, and a pacemaker was implanted. There were no complications. The other 2 patients were referred to surgery for cryoablation of the atrioventricular junction. Patients were followed for an average of 21 +/- 12 months. Four patients have died: two due to congestive heart failure, which was present prior to the ablation procedure, the third because of a metastatic carcinoma, and the fourth had a sudden death 14 months after the procedure (he had dilated cardiomyopathy and Wolff-Parkinson-White syndrome). The remainder in chronic stable complete atrioventricular block are asymptomatic for arrhythmias and without antiarrhythmic medication.
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PMID:[The interruption of atrioventricular conduction by cardiac fulguration in patients with supraventricular tachycardias. The mid- and long-term results]. 154 59

Three cases of symptomatic bradycardia due to topical ocular timolol administration are reported. Two patients had syncope related to atrioventricular block, and the other one complained of dizziness due to sinus bradycardia. Heart disease was not present in any case, although a right bundle branch block was observed in one patients. A normal sinus rhythm resumed in all patients after discontinuation of timolol.
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PMID:[Bradyarrhythmias secondary to the use of ophthalmic timolol. A report of 3 cases]. 154 65

Electrocardiographic abnormalities are often found in older patients, but their prevalence in free-living elderly populations is not well-defined. In addition, the clinical significance of many of these abnormalities is uncertain. The prevalence of major electrocardiographic abnormalities was determined in 5,150 adults aged greater than or equal to 65 years from the Cardiovascular Health Study--a study of risk factors for stroke and coronary heart disease in the elderly. Ventricular conduction defects, major Q/QS waves, left ventricular hypertrophy, isolated major ST-T-wave abnormalities, atrial fibrillation and first-degree atrioventricular block were collectively categorized as major electrocardiographic abnormalities. Prevalence of any major electrocardiographic abnormality was 29% in the entire cohort, 19% among 2,413 participants who reported no history of coronary artery disease or systemic hypertension, and 37% among 2,737 participants with a history of coronary artery disease or hypertension. Prevalence of major electrocardiographic abnormalities was higher in men than in women regardless of history, and tended to increase with age. Major Q/QS waves were found in 5.2%, and more than half were in those who did not report a previous myocardial infarction. Major electrocardiographic abnormalities are common in elderly men and women irrespective of the history of heart disease.
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PMID:Major electrocardiographic abnormalities in persons aged 65 years and older (the Cardiovascular Health Study). Cardiovascular Health Study Collaborative Research Group. 158 68


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