Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “Heart Block”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 235 records · Page 13Linked to original sources
PubMed1975

Familial atrioventricular heart block; an autosomal dominant trait.

A family of 28 individuals spanning four generations was investigated because of a finding of complete heart block in five members and the existence of a low degree of atrioventricular (A-V) heart block in a sixth member. The disorder was characterized by 1) adult onset in all, 2) complete A-V heart block in five and first degree A-V heart block in one, 3) sinus bradycardia in three, 4) atrial fibrillation in five, 5) abnormal QRS complex in five, 6) ventricular tachycardia in three, 7) left ventricular enlargement in all, and 8) mitral insufficiency in five. Proximal location of the A-V heart block was suggested by the fact that atropine caused acceleration of the ventricular rate and by the presence of a His bundle potential preceding the QRS complexes. Involvement of the distal conducting system was indicated by the widened QRS complex and a prolonged H-V interval. Pathologic examination in one case showed extensive sinus node fibrosis and interruption of the A-V node-His bundle connection. This disorder is probably due to an autosomal dominant trait.

Adult↗
PubMed1999

Heart Block and Conduction Disturbances.

Heart block and conduction disturbances appear to be relatively common in the general population. Because many individuals with conduction system disease are asymptomatic and never seek medical attention, our knowledge of the natural history of these disorders comes from large population-based studies. Because conduction system disease is a heterogeneous entity of diverse causes, treatment options may vary from individual to individual, depending on the specific cause and the clinical manifestations. Permanent pacing is the cornerstone of treatment for most patients with symptomatic conduction system disease. Recent technologic improvements in permanent pacing systems have made this option more attractive, although there are situations in which other therapeutic options may be considered. Specific therapy is not necessary in all patients with conduction system disease, especially those without symptoms. Of those requiring treatment, medication may be helpful in certain situations, but pacemakers remain the mainstay of therapy in most. Recent advances in the therapy of ischemic heart disease (eg, thrombolytic agents and reperfusion techniques) show some promise in arresting or even reversing some forms of conduction system disease, but these techniques require further study.

Journal Article↗
PubMed1982

Experimental production of complete heart block by electrocoagulation in the closed chest dog.

Methods for producing complete heart block in experimental animals have usually required thoracotomy to gain access to the intracardiac conduction system. A closed chest technique has been developed for producing discrete permanent lesions in the atrioventricular node or His bundle of anesthetized dogs. An insulated transseptal needle is passed through a venous catheter to the right atrium. The exposed tip is pressed into the His bundle and a 30 to 40 joule pulse from a DC defibrillator is transmitted through the needle. This produces a 1 to 3 mm diameter coagulative lesion which permanently destroys the tissue at this point. The process can be repeated until complete heart block is achieved. Our procedure has been successful in 45 of 46 attempts to prepare dogs for acute experiments and, using implanted pacemakers, for chronic studies. We conclude that this closed chest method is a safe and reliable alternative for production of complete heart block requiring thoracotomy, thereby providing an important new means for both acute and chronic experimental studies requiring complete heart block for the improved elucidation of mechanisms and management of cardiovascular diseases.

Animals↗
PubMed1975

Complete heart block as a consequence of atriondal discontinuity.

We have recently studied a case of complete heart block in which there was considerable difficulty in deciding whether it was of congenital or acquired origin. This was because the heart block was first discovered at the age of 2 years in the course of acute diphtheria. Though diphtheritic infections are known to affect the cardiac conduction system, authenticated cases of post-diphtheritic block persisting after the infection are rare, and, furthermore, histopathological study in this case revealed discontinuity between the atrial tissues and the more peripheral parts of the atrioventricular conduction tissues. This has been more commonly observed in congenital cases of complete heart block and it has been postulated on theoretical grounds that this could be thebasis for congenital heart block; on the other hand, it has been noted in a single casethought to be of acquired origin. Review of the evidence available failed to allow accurate classification of the case into either congenital or acquired categories. Thenormal, segmental development of the atrioventricular node, each segment being of different embryological origin, is discussed and the case presented is understandable in thelight of this.

Adult↗
PubMed1989

Family studies of congenital heart block associated with Ro antibody.

Complete congenital heart block is associated with the presence of maternal autoantibodies to small ribosomal nucleoproteins (such as anti-Ro) which cross the placenta and may be deposited at the site of cardiac damage. Ten such cases of congenital heart block, their mothers, and their siblings were studied. The seropositive mother of one case had a similar conduction defect (bifascicular block) to that in her affected child. None of the siblings examined had cardiac lesions. Six mothers had Ro or La antibody five to 17 years after the birth of the affected child. Four mothers examined 11-32 years after the birth of an affected child were seronegative. Three of these mothers had evidence of a connective tissue disorder. This evidence is consistent with a hypothesis that a maternal viral infection, associated with autoantibody production, leads to virus crossing the placenta, damaging the fetal heart, and eliciting local deposition of maternal antibody.

Adolescent↗
PubMed1999

Latex anaphylaxis causing heart block: role of ranitidine.

PURPOSE: Treatment with H2 receptor antagonists may cause the heart to be more susceptible to atrioventricular conduction delay when exposed to an overwhelming insult by histamine released during an anaphylactic reaction. We present the case of a woman, pretreated with ranitidine, who developed 3:1 heart block secondary to latex anaphylaxis. We propose that H2 antagonist premedication alone in patients susceptible to anaphylaxis increases their risk of heart block. CLINICAL FEATURES: A 38 yr old obese woman with cervical cancer presented for a radical hysterectomy. Systems review yielded a history of sleep apnea, orthopnea, gastroesophageal reflux, and sciatica. Medications included preoperative ranitidine, 150 mg. There was no history of atopy or allergy. Following general anesthesia induction, at the onset of the surgical procedure the patient developed a severe anaphylactic reaction which was heralded by the onset of 3:1 heart block, with decreases in SpO2, P(ET)CO2 and a decrease in systolic blood pressure to 45 mmHg. This was diagnosed as a possible latex reaction and treated using epinephrine boluses and infusion, fluids, 50 mg diphenhydramine, 50 mg ranitidine and 100 mg hydrocortisone. Following a 48 hr stay in the ICU the patient made an uneventful recovery. Allergy testing with intradermal latex injection and increased plasma tryptase levels confirmed a latex anaphylaxis. CONCLUSION: The use of H2 antagonists alone as a prophylaxis for gastroesophageal reflux may increase the risk of heart block in patients who develop anaphylaxis.

Adult↗
PubMed1983

Acute nonspecific carditis with advanced heart block in Malaysians.

Acute nonspecific carditis with advanced heart block is rare. We observed nine cases with complete heart block and one with Mobitz type II block over an eight and a half year period. Temporary cardiac pacing was instituted in all while permanent pacing was required in six patients. No death was recorded.

Acute Disease↗
PubMed1989

Complete heart block in the 18p--syndrome. Congenital calcification of the atrioventricular node.

Complete heart block exists when the atria and ventricles beat completely independently of each other. It is heterogeneous with respect to pathogenesis. Occasionally, complete heart block may be symptomatic in infancy. Rarely, it is associated with genetic syndromes. Cardiac abnormalities are unusual in the 18p-syndrome. We describe a female stillborn infant who had 18p-syndrome with hydrops fetalis and complete heart block secondary to atrioventricular node calcification.

Abnormalities, Multiple↗
PubMed1979

Echocardiography and fetal heart sounds in the diagnosis of fetal heart block.

A 32-week fetus was demonstrated phonocardiographically and echocardiographically to have a regular atrial rate of 150 per minute and a regular ventricular rate of 39 per minute, indicating complete heart block. The diagnosis was suspected when two groups of heart sounds at two distinct rates were heard on auscultation, and was confirmed by the postnatal ECG. The maternal history was significant for the presence of systemic lupus erythematosus. The basis for the echocardiographic diatnosis of complete heart block, the presence of atrial heart sounds in complete heart block, and the relationship of maternal SLE to congenital heart block are discussed.

Adult↗
PubMed2000

Cardiac hydatid cyst revealed by complete heart block.

Hydatid cyst of the heart is an uncommon lesion. The infection is most common in sheep-raising areas of the world. We report a rare case of cardiac hydatid cyst revealed by complete heart block, which was removed with the patient under cardiopulmonary bypass. This case stresses the importance of echocardiography for the diagnosis of cardiac echinococcosis.

Adult↗
PubMed1995

Increased propensity of women to develop torsades de pointes during complete heart block.

INTRODUCTION: To determine whether an increased female gender susceptibility to torsades de pointes (TdP) may exist in a clinical model of bradycardia-induced long QT syndrome, we investigated reported cases of TdP associated with acquired complete heart block. METHODS AND RESULTS: Seventy-two cases reported in the medical literature dating from 1941 through 1993 were identified, all describing TdP or "transient ventricular tachycardia/fibrillation" (to include those cases reported prior to the use of TdP terminology) in the setting of acquired complete heart block unassociated with QT prolonging drugs. Expected female prevalence in complete heart block was estimated at 52%, based on projections derived from 206,016 hospital discharges in the National Inpatient Profile (Commission on Professional and Hospital Activities, Ann Arbor, MI), over the years 1985 through 1992. During complete heart block, mean heart rate was 37 beats/min in both sexes (combined n = 43), and absolute QT interval ranged from 0.52 to 0.88 seconds, with a mean of 0.68 seconds (n = 25). Female prevalence among patients with TdP during complete heart block was greater than expected: 72% for all studied cases (P < 0.001); 70% (P < 0.04) and 74% (P < 0.02) among those reported prior to (n = 35) and during or after (n = 37) 1980, respectively; 73% (P < 0.03) among those with documented normokalemia (n = 26); and 68% (P = 0.2) among those with a prolonged QT interval and known polymorphic VT (i.e., unequivocal TdP; n = 25). CONCLUSION: Despite inherent limitations of this retrospective study, the data are consistent in suggesting a greater than expected female prevalence among patients with TdP related to complete heart block. This finding lends support to a broadening concept of increased susceptibility of women to the development of TdP in various settings of QT prolongation.

Adult↗