Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0018799 (heart disease)
 34,133 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Fifty-eight patients (29 M, 29 F, mean age 60.8 +/- 16 years) with unexplained syncope at the end of a complete clinical and electrophysiological evaluation, were followed for a mean period of 36.6 +/- 20.5 months (median: 30.5 months). Structural heart disease was present in 32 patients (55.2%). The standard ECG was normal in 24 (41.4%) and showed sinus bradycardia (greater than 40 m-1) and/or first degree AV block and/or intraventricular conduction disturbances in 29 patients (50%). During follow-up, recurrences of syncope were observed in 11 of 43 untreated patients (25.6%), three of seven electrically treated patients (42.9%) and two of eight pharmacologically treated patients (25%). The cause of these recurrences was cardiac in one (1.7%), non-cardiac in 10 (17.2%) and remained undetermined in five (8.6%). Sudden death occurred in only one patient (1.7%), who was receiving chronic amiodarone therapy. These results indicate that (1) syncopal recurrences may occur in an appreciable percentage of patients with unexplained syncope and a negative electrophysiologic study during a relatively long-term follow-up, (2) syncopal recurrences, when they occur, are generally due to a non-cardiac cause, (3) sudden death is an occasional and rare event in this patient population and (4) empirical prophylactic treatment with a permanent pacemaker or antiarrhythmic drugs does not usually prevent complications during the follow-up.
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PMID:Long-term follow-up of patients with unexplained syncope and negative electrophysiologic study. 292 82

Twenty-five cases of double-inlet left ventricle, 23 in atrial situs solitus and 2 with dextroisomerism are described. Twenty had both atrioventricular valves and in 3 a common atrioventricular valve connected to the left ventricle. In rest, the left atrioventricular valve was straddling over the left-sided right ventricle in about 15%. The position of the rudimentary right ventricle varied from superior, anterior and to the right of left ventricle (6 with transposition and 9 with concordant ventriculo arterial connection), to superior anterior and to the left of left ventricle (10 cases, all with transposition). Five cases had stenosis of the left atrioventricular valve and 2 stenosis of the right one. In 11, the clinical presentation was dominated by cyanosis, reduced pulmonary blood flow and right to left shunt. The rest had cyanosis and congestive heart failure. Five patients with right ventricle on the left had complete atrioventricular block, 9 right AQRS orientation and all of them findings of left ventricle hypertrophy. Three cases showed initial Q wave in VI and one left bundle branch block. Cases with right ventricle on the right, had left QRS orientation, left ventricle hypertrophy and 2 complete atrioventricular block. Cross-sectional echoes showed in 13, two atrioventricular valves committed to the left ventricle; in 3 of them the right ventricle was visualized. In 22 cases angiography determined the type of atrioventricular connection. Double inlet left ventricle is one of the most challenging diagnosis in congenital heart disease. Considering its lack of clinical specificity and according to our results, the electrocardiogram, echocardiogram and angiographic findings are of great help for its identification.
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PMID:[Double inlet left ventricle]. 294 47

Eppinger and Rothberger in 1909 and 1910 first acknowledged the importance of the conduction system, yet a confusion of the pattern of left bundle branch block with right bundle branch block resulted which persisted for 25 years. In left bundle branch block, right ventricular endocardial activation begins before, and is often completed before, initiation of left ventricular endocardial activation. Most likely, right to left septal activation then follows, resulting in left ventricular endocardial activation. Although it is hazardous to make definitive diagnoses of infarction in the presence of left bundle branch block, clues do exist. Benign left bundle branch block is rare; usually disease becomes manifest. Electrocardiographic criteria of hypertrophy are not as helpful in older patients with chronic left bundle branch block (mainly because of the very high incidence of left ventricular hypertrophy) as in younger patients with block of nonatherosclerotic origin. Left bundle branch block is often associated with other abnormalities of the conduction system. Fascicular blocks may mask or mimic myocardial infarction. Left posterior fascicular block is most often an indicator of left ventricular myocardial deficit if right ventricular enlargement is eliminated. Mortality is higher in patients with associated left axis deviation than in those with a normal axis, although the incidence of progression of atrioventricular (AV) block is low. In symptomatic patients with prolonged His to ventricular intervals, the incidence of progression of AV block is higher (12%). Preexisting left bundle branch block in the absence of clinical evidence of heart disease is rare, yet carries with it a slightly increased mortality. Newly acquired left bundle branch block carries a 10-fold increase in mortality; the incidence of sudden death as the first manifestation of heart disease is increased 10-fold.
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PMID:Left bundle branch block: a continuously evolving concept. 295 Jan 57

Propafenone is a new class Ic antiarrhythmic compound with a broad pharmacologic profile. In this study, its dose-response relationship was examined in a double-blind, randomized, placebo-controlled five treatment parallel design protocol. Patients enrolled had heart disease with Lown grade 2 premature ventricular contractions (PVCs) (greater than or equal to 30/hr) documented on 24-hour Holter recordings. Propafenone was compared in four doses (337.5, 450, 675, and 900 mg/day) to placebo. The double-blind phase lasted 2 weeks. Two hundred twenty-six patients were enrolled, of whom 171 were men and 55 were women; their mean age was 59.8 years and 85% were Caucasian and 4% were black. The arrhythmias were symptomatic in 173. Twenty (8.8%) withdrew from the study before completion: 15 had adverse reactions, two had intercurrent illnesses, and three withdrew for administrative reasons. In one patient, the density of arrhythmia appeared to increase with propafenone. Side effects were of central nervous system or gastrointestinal origin; less than 5% of patients developed first-degree atrioventricular block or intraventricular conduction defect. There were no deaths in the study. The occurrence of side effects was not related to dose. Propafenone had no effect on heart rate. It increased the PR interval at all doses (9% to 22% compared to placebo at baseline; p less than 0.01) at 450 to 900 mg/day after 2 weeks of therapy. The drug increased the QRS duration at all doses, highly significantly at 675 mg/day (8.5 msec; p less than 0.01) and at 900 mg/day (15.7 msec; p less than 0.01) after 2 weeks of therapy. Only at the highest dose was the QTc slightly but significantly (14.3 msec; p less than 0.01) increased. Propafenone exerted a dose-dependent effect on PVCs recorded on serial 24-hour Holter recordings: compared to placebo, at 2 weeks 337.5 mg/day reduced PVCs by 70.8% (p less than 0.05), 450 mg/day reduced PVCs by 82.0% (p less than 0.01), 675 mg/day reduced PVCs by 90.2% (p less than 0.01) and 900 mg/day reduced PVCs by 95.3% (p less than 0.01). The effects of the two highest doses of propafenone were significantly greater than those of 337.5 mg/day. In 68% of the patients receiving 900 mg/day, 80% or greater reduction in total PVCs was found. In addition, there was a greater than 90% decrease in ventricular couplets, and 96% decrease in ventricular tachycardia (VT) beats. Propafenone eliminated PVCs in 8% of all patients, ventricular couplets in 58%, and VT beats in 91%.(ABSTRACT TRUNCATED AT 400 WORDS)
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PMID:Effects of propafenone on ventricular arrhythmias: double-blind, parallel, randomized, placebo-controlled dose-ranging study. 305 44

There are relatively few reported studies of continuous electrocardiographic recordings by the Holter method in children. We report our experience of 296 24-hour recordings in 160 patients (average age 10.5 years), investigated for suspected or known cardiac arrhythmias. One hundred and ten patients (68.75%) had no organic heart disease and 6 patients (3.75%) had acquired lesions. Eighty-three patients (52%) were symptomatic. Sixty-three patients (39%) had normal recordings; 97 patients (61%) had a total of 126 arrhythmias. There were 45 cases of atrioventricular block, 24 cases of sinus node dysfunction, 39 cases of supraventricular arrhythmias and 18 cases of ventricular arrhythmias. Overall, 47.6% of these rhythm disturbances were diagnosed by Holter monitoring. This technique was particularly valuable in the diagnosis of arrhythmias in symptomatic patients, patients with arrhythmogenic cardiac lesions and in the detection and surveillance of postoperative arrhythmias in congenital heart disease, of pacemakers, of congenital atrioventricular block and of the chronic arrhythmias of childhood.
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PMID:[Continuous electrocardiographic recording with the Holter method in children. Indications and results]. 310 70

Between July, 1967 and December, 1987, 71 children and adolescents (43 boys, 28 girls) aged from 9 days to 20 years (mean 7.8 years) underwent pacemaker implantation. In 91 p. 100 of the cases this treatment was performed for complete atrioventricular block (CAVB). Surgical CAVB was the reason for 59 p. 100 of implantations (correction of tetralogy of Fallot and, more recently, of complex cardiopathies), the second main reason (16.9 p. 100) being nonsurgical CAVB associated with heart disease; the children in this group were young (mean age 4.2 years), and the prognosis mainly depended on the heart disease. Isolated congenital CAVB accounted for only 8.5 p. 100 of pacemaker implantations; these were older children (mean age 13.7 years), and the decision to implant was often difficult to reach in the absence of major functional disorders; following implantation, it was frequently found that isolated congenital CAVBs regarded as being well tolerated in fact were unrecognized handicaps. Acquired CAVB (7 p. 100) mostly consisted of Kearns' syndrome (4/5 cases). In addition, 3 children with sinus node disease and 1 with Romano-Ward syndrome benefited from cardiac pacing. Seven children died; death was in no case due to pacing but to the heart disease associated with CAVB. Endocardial pacing (68.2 p. 100 of primary implantations during the last decade) was preferred to epicardial pacing. Since 1985 we have been using exclusively screwed endocardial monopolar electrodes. The pacemakers were usually of the single-chamber ventricular type (85.9 p. 100 of primary implantations), but since 1987 dual-chamber pacemakers have been increasingly preferred for children with permanent CAVB or for replacement of pacemaker cases. Single-chamber noncompetitive ("demand") pacemakers were implanted in only 2 children: one pacemaker was connected to a ventricular electrode (atrial paralysis), the other to an atrial electrode. Whatever the type of electrode used, the pacemakers were implanted in the abdominal region in very young infants and in the pectoral region in children older than 3 or 4 years. Breakage of the wire was the main complication. Rises in threshold are the major drawback of epicardial pacing, as they require reoperation when the energy delivered cannot be effectively programmed. Endocardial pacing, preferably with a dual-chamber instrument, seems to be the best method, being the least aggressive, with minimal complications in short and very long term; it is justified as first-line treatment of permanent or predominant CAVB.(ABSTRACT TRUNCATED AT 400 WORDS)
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PMID:[Cardiac stimulation in children. 20 years' experience]. 313 30

Complex congenital heart disease with atrioventricular block was detected prenatally in two fetuses at 34 and 28 weeks' gestation. The spleen was not seen on ultrasonographic examination in either fetus, suggesting polysplenia/asplenia syndrome. Both infants died shortly after delivery and the autopsies confirmed this diagnosis. Recommendations for sonographic screening of the fetal spleen in cases of prenatal detection of complex heart disease or cardiac dysrhythmia are discussed.
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PMID:Prenatal diagnosis of asplenia/polysplenia syndrome. 336 89

Transesophageal atrial pacing was used to evaluate the cause of palpitations in 28 patients ages 3 to 18 years (mean 11). Palpitations were defined as the sustained (seconds to minutes) sensation of rapid heart beating. Each patient had had greater than 2 episodes of palpitations. No patient had other evidence of heart disease. Standard electrocardiogram was normal (23 of 28 patients), demonstrated ventricular preexcitation (3 of 28 patients) or demonstrated short PR interval (2 of 28 patients). In selected patients, ambulatory monitoring (11 patients) or exercise testing (3 patients) was performed but failed to demonstrate a cause of palpitations. In an effort to initiate tachycardia, a similar transesophageal atrial pacing protocol was performed in each patient. The protocol consisted of: (1) single extrastimuli at progressively closer intervals during sinus rhythm and after an 8-beat pacing train at greater than or equal to 1 cycle lengths and (2) incremental atrial pacing to the point of second-degree atrioventricular block. If this pacing regimen failed to initiate tachycardia, it was repeated during isoproterenol infusion (0.02, 0.05 and 0.1 micrograms/kg/min) and then following intravenous atropine (0.04 mg/kg) administration. During the study, tachycardia was initiated in 20 of 28 patients (71%) (14 of 15 patients greater than 10 years, 6 of 13 patients less than or equal to 10 years; p less than 0.01, Fisher's exact test). Electrophysiologic characteristics of induced tachycardia suggested reentry within the atrioventricular node (8 of 20 patients) or orthodromic reciprocating tachycardia (12 of 20 patients). In 3 of 12 patients with orthodromic reciprocating tachycardia, a transition to atrial fibrillation was observed.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Role of transesophageal pacing in evaluation of palpitations in children and adolescents. 341 49

The success rate of direct-current (DC) countershocks and postshock arrhythmias are of concern for the design of automatic devices. Results of 112 DC shocks for induced ventricular tachycardia/fibrillation (VT/VF) (n = 99) or atrial fibrillation (AF) were analyzed. Clinical and arrhythmia characteristics were related to the success rate of DC shocks as well as postshock arrhythmias. Sixty-one patients were men and 14 were women; mean age was 52 +/- 15 years. Coronary artery disease was present in 56 patients and cardiomyopathy in 4. The other patients had no apparent structural heart disease. The success rate of transchest DC shocks for VT and VF were identical. The first DC shock interrupted 80% of VT and VF episodes. All episodes were terminated by 4 or fewer DC shocks. A single DC shock changed morphologic pattern or rate of 4 episodes of VT. Asystole after VT/VF (1,900 +/- 960 ms) was longer than after atrial fibrillation (1,150 +/- 470 ms, p less than 0.01). VT/VF recurred (within 3 minutes) after 26 of 99 initially successful DC shocks, requiring repeat shocks in 2 cases. Sinus bradycardia (n = 18) or high degree atrioventricular block (n = 11) necessitated rate support pacing in 10 patients. Antiarrhythmic drugs did not prevent postshock tachycardias, but facilitated the development of bradycardias. In conclusion, reliable and continuous analysis of cardiac rhythm after discharge is mandatory to enable automatic devices to correct unsuccessful discharges or recurring VT/VF. In addition, demand pacing capability is desirable to prevent severe bradycardia after DC shocks in patients receiving antiarrhythmic drugs.
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PMID:Dysrhythmias after direct-current cardioversion. 351 May 22

This article addresses electrophysiologic evaluation of the distal AV conduction system in patients with chronic bifascicular block. It was formerly thought that progression to complete AV block was a common cause of morbidity and even sudden death in this condition, and it was hoped that electrophysiologic evaluation, including measurement of the H-V interval, would facilitate prospective identification and prophylactic treatment of patients prone to these complications. However, a decade of clinical investigation has revealed that progression to complete AV block is rare and that although cardiovascular mortality, including sudden death, is substantial, this mortality usually relates to underlying organic heart disease. The current role for electrophysiologic studies in chronic bifascicular block is limited to delineation of the site of electrocardiographically documented second- or third-degree AV block and to the evaluation of unexplained syncope.
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PMID:Distal atrioventricular conduction system function. 353 Apr 65


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