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

A 21-year-old black man without history of heart disease had severe sinus bradycardia and intermittent second-degree AV block after the use of marijuana. After he had abstained from marijuana for 72 hours, the AV block disappeared. We have discussed possible effects of marijuana on the cardiovascular system.
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PMID:Marijuana and second-degree AV block. 626 3

Fifteen patients aged 59.3 +/- 11.5 years (mean +/- standard deviation [SD]) had recurrent symptomatic ventricular tachycardia (VT) refractory to at least 2 conventional antiarrhythmic drugs. All patients had organic heart disease; 4 had an acute myocardial infarction. The mean ejection fraction was 0.30 +/- 0.09. TWelve patients had overt congestive heart failure. Five had bundle branch block. Before treatment with intravenous amiodarone, the patients had had 6 to 40 episodes of symptomatic VT over 1 to 8 days of hospitalization. All patients received an initial bolus of 5 mg of amiodarone/kg over 15 minutes. Seven patients also received a continuous infusion of 600 to 1,000 mg of amiodarone over 12 to 24 hours. Additional doses depended on the patients' clinical responses. In 11 of 15 patients, antiarrhythmic drugs that had failed to suppress VT were continued during administration of amiodarone. In 12 of 15 patients acute control of VT was obtained with intravenous administration of amiodarone either alone or in combination with previously ineffective drugs. Three patients continued to have frequent episodes of VT while being treated with intravenous amiodarone. Mobitz type I atrioventricular block developed in 1 patient. No patient had high degree atrioventricular block, symptomatic hypotension, or a clinically apparent worsening of congestive heart failure. The use of intravenous amiodarone represents a significant advance in the acute treatment of frequent life-threatening VT refractory to other drugs. With appropriate monitoring, it can be used safely in patients with congestive heart failure, bundle branch block, or acute myocardial infarction.
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PMID:Intravenous amiodarone in the acute treatment of recurrent symptomatic ventricular tachycardia. 640 73

Sixteen patients, aged 4 to 42 years, operated for congenital heart disease, presented, months or years after surgery, complete atrioventricular (11 cases) or sinoatrial block (5 cases). Six patients had transient complete atrioventricular block in the immediate postoperative period, the maximum duration of which was less than 30 days. The late postoperative period was defined as at least 6 months after surgery. The period between surgery and the implantation of a pacemaker varied from 9 months to 19 years, average 6,3 years. Analysis of long term electrocardiographic studies distinguished three types of progression: --group I: alternation of sinus rhythm and conduction defect until definitive block, sometimes presenting with syncope; --group II: sudden, severe conduction defect after a long period of sinus rhythm; --group III: progressive lengthening of the PR interval. Seven patients developed syncope; 4 had dizziness, 2 were short of breath; only 3 were asymptomatic. All underwent permanent pacing. The incidence of late conduction defects appears to be 1 to 2% of operated patients. The causes include progressive fibrosis, slow sclerosis extending over conduction pathways which are congenitally fragile. Most late blocks are of an advanced degree. Some may be responsible for unexplained sudden death. It is therefore desirable to avoid this complication by the judicious and considered implantation of a cardiac pacemaker. Some authors mention the following factors in deciding on the indications for pacing: --complete, transient atrioventricular block during the operation or the immediate postoperative period; --ECG appearances of right bundle branch block and left anterior hemiblock, or trifascicular block; --His bundle studies.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:[Severe postoperative heart blocks appearing late. 16 cases]. 641 89

Serial sections of the atrioventricular (AV) conduction system were microscopically studied in 12 autopsied hearts: four with complete type common AV orifice (CAVO), two with atrial septal defect of the ostium primum type (ASD-I), two with ventricular septal defect of the persistent common AV canal type (VSD-C) and four without heart disease. The anatomic findings were semiquantitatively compared with the normal control using Feldt's method and correlated to the mean frontal QRS axis on ECG. The cases of CAVO or VSD-C with left axis devation invariably showed similar patterns regarding the location and course of the AV conduction system: (1) posterior displacement of the AV node, (2) relatively short distance between the AV node and the beginning of the left bundle branch (LBB), and (3) postero-inferior displacement of the bundle of His and the LBB. The postero-inferior displacement of the LBB seemed to be responsible for left axis deviation. The cases of ASD-I showed some additional findings: (1) impaired contiguity between the AV node and the bundle of His might have caused the occasional advanced AV block in one case, and (2) the posterior radiation of the LBB traversed down through the branch-free muscle bundle, which was assumed to be related to the right axis deviation in the other case. These findings suggest that the disposition of the AV conduction system in CAVO and in its related anomalies were basically the same whatever the type of defect, and this was considered to be correlated to the established ECG pattern.
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PMID:Histopathological correlation between the QRS axis and disposition of the atrioventricular conduction system in common atrioventricular orifice and in its related anomalies. 665 91

The records of 22 patients with transient atrioventricular (AV) block after open-heart surgery for congenital heart disease from 1972 to 1978 were reviewed to determine the natural history of this entity. Preoperatively, no patient had AV block; 3 had right bundle branch block (BBB), 1 had left BBB and 5 had nonspecific intraventricular conduction delay. Complete AV block developed in 20 patients and Mobitz II AV block in 2. Transient AV block occurred intraoperatively in 14 patients and within 48 hours postoperatively in 8; AV block persisted for greater than or equal to 48 hours postoperatively in all patients, for a mean of 7.3 days (range 2 to 28). During a follow-up of 5.5 years (range 2.5 to 10), late AV block developed in 2 patients. None of the 18 patients whose escape QRS complex morphology during AV block was similar to the final QRS complex during normal sinus rhythm or atrial fibrillation with AV conduction had late AV block, whereas 2 of the 4 in whom it differed did (p less than 0.01). There was no difference in the escape rate between the 2 groups. Thus, late development of high-grade AV block is infrequent among patients with transient postoperative AV block. An escape QRS complex during postoperative AV block that differs from the QRS complex seen on recovery of normal sinus rhythm or atrial fibrillation with anterograde conduction may identify those at high risk of late AV block.
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PMID:Transient atrioventricular block after open-heart surgery for congenital heart disease. 669 Dec 62

During a baseline cardiovascular survey PR was measured in a strictly standardized way in 1832 men aged 40-59 years, free from coronary heart disease (CHD). Of 1758 men still alive, 1585 underwent an identical follow-up study 7 years later. A total of 1570 were in sinus rhythm. The following findings were made: (1) Baseline and follow-up prevalence of a prolonged PR (greater than or equal to 0.22 s) was identical (5.3 vs. 5.4%). (2) Only 60% of restudied men with a prolonged PR also had prolonged PR at follow-up. (3) Only 1 of 98 with a prolonged baseline PR had a more advanced AV block at follow-up, whereas an additional 4 had conditions which might influence the AV node (1 Bechterew's disease and 3 mild aortic valve stenosis). (4) The incidence of all CHD events found during the follow-up study (CHD deaths, myocardial infarction, angina pectoris, and pathologic exercise ECGs) was moderately but significantly lower in men with a prolonged PR than among men with a PR less than or equal to 0.21 s. Thus a prolonged PR is rarely an indicator of impending, more severe conduction disturbances; it is mostly a benign, functional finding in middle-aged men free from overt heart disease and is not positively associated with CHD. Rather PR may be moderately and inversely associated with latent CHD.
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PMID:Natural course of a prolonged PR interval and the relation between PR and incidence of coronary heart disease. A 7-year follow-up study of 1832 apparently healthy men aged 40-59 years. 670 91

The association of complex congenital heart disease with asplenia syndrome and congenital AV block is described in a newborn. Cardiovascular lesions were right atrial isomerism, d-loop, discordant ventriculoarterial connection, pulmonary stenosis, total anomalous pulmonary venous drainage, absent right pulmonary artery, and bilateral superior vena cava. The ECG recording disclosed complete AV block with narrow QRS (suprahisian block). The histology of the conduction system revealed two AV nodes, one anterior and one posterior, none of which connected with the atrial myocardium; only the posterior node was continuous with a penetrating and bifurcating bundle. The histologic findings were consistent with the suprahisian AV block due to lack of connection between the atria and the regular posterior AV specialized junction.
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PMID:Congenital atrioventricular block in right atrial isomerism (asplenia). A case due to atrionodal discontinuity. 670 90

Twenty-four-hour ambulatory electrocardiography was performed in 25 young and 29 active elderly subjects. Sinus bradycardia and sinus arrhythmia were common in the young but uncommon in the elderly. Ventricular and supraventricular premature beats and brief runs of supraventricular tachycardia were common in the elderly but uncommon in the young. Complex ventricular arrhythmias only occurred in the elderly but brief episodes of nocturnal Wenckebach AV block were quite common in young and old alike. No significant difference in arrhythmia frequency was found between elderly subjects with heart disease and those without heart disease or between elderly subjects without symptoms and those with non-episodic symptoms such as dizziness. None of the arrhythmias in the young or elderly subjects was associated with symptoms. In follow-up at 30 months, only one elderly subject was deceased (from pneumonia) and none had suffered a stroke or heart attack. It is concluded that transient cardiac arrhythmias are commoner in the elderly than in the young. However, their long-term significance remains unknown, but it is likely that they are relatively benign.
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PMID:The significance of cardiac arrhythmias in the aged. 684 89

To investigate the genesis of the initial low frequency component of the first heart sound that precedes the high frequency vibrations associated with closure of the atrioventricular valves, echophonocardiograms of 36 persons were recorded. These included 10 normal subjects and 26 patients with various types of heart disease including mitral valve replacement. Electrocardiograms demonstrated normal sinus rhythm in 23 subjects, atrial fibrillation in 9, complete atrioventricular block in 2 and atrial flutter in 2. In the phonocardiogram, the low frequency component of the first heart sound followed the onset of the QRS complex and preceded the first high frequency component of this sound. The low frequency component occurred simultaneously with the beginning of the final fast closing movement of the mitral valve on the echocardiogram and was found both in normal rhythm and in arrhythmias. However, in arrhythmias its intensity varied on a beat to beat basis, being loudest after a short RR interval or when atrial systole occurred very close to the expected time of ventricular systole. In patients in whom apexcardiograms were recorded, the low frequency component was coincident with or very close to the onset of ventricular systole. It is concluded that the low frequency component of the first heart sound represents vibrations caused by contraction of the left ventricle and deceleration of antegrade blood flow across the mitral valve. Neither atrial contraction nor mitral valve tension is necessary for the production of this soft initial component.
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PMID:Echophonocardiographic study of the initial low frequency component of the first heart sound. 687 7

Serial His bundle recordings were obtained during 1:1 atrioventricular (AV) conduction in 90 patients with chronic bundle branch block over a mean interval of 30 months. Atrioventricular conduction time (AH) increased greater than or equal to 10 msec in 25 (28%) and infranodal conduction time (HV) increased greater than or equal to 8 msec in 29 (32%), but only 10 patients had parallel increases in AH and HV intervals. Increases in conduction times were independent of age, time interval between studies, cause of heart disease or initial AH or HV intervals. Women were significantly more likely than men to show an increased HV interval and spontaneous trifascicular block. Spontaneous progression to second- or third-degree AV block occurred at the AV node in seven patients and below the node in 12 patients. The initial AH interval was prolonged in five of seven patients (71%) with AV nodal block and had increased further in only two at restudy. The initial HV interval was abnormal in eight of 12 patients (67%) who progressed to infranodal block and was prolonged further in eight at restudy. We conclude that in patients with chronic bundle branch block, (1) approximately 33% show progressive AV conduction system disease and AV nodal and infranodal disease progress independently; (2) progression of infranodal disease is more common in women; (3) AV nodal disease progress independently; (2) progression of infranodal disease is more common in women; (3) AV nodal disease is a common cause of AV block and can occur without further prolongation of the AH interval once a critical level of disease is attained, whereas infranodal block is usually accompanied by progressive lengthening of the HV interval; and (4) progression of AV conduction disease is not readily predictable from clinical and electrophysiologic variables.
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PMID:Serial electrophysiologic studies in patients with chronic bundle branch block. 707 4


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