ISSN:0009-7322    

出版商:OVID    

年代:1976

数据来源: OVID

ISSN:0009-7322    

出版商:OVID    

年代:1976

数据来源: OVID

摘要:

Although considerable information is available concerning the clinical features and natural history of asymmetric septal hypertrophy (ASH) in adults, little is known of this disease in children. The clinical characteristics and course of 46 children with ASH, who were evaluated at the National Heart and Lung Institute, have been analyzed. Twenty-four children had obstruction to ventricular outflow; 22 children had no obstruction to ventricular outflow, including 11 patients without overt manifestations of cardiac disease other than echocardiographic evidence of ASH. Thirty-five of the 46 children have been followed for one to 16 years (average 7.4 years). These latter children represent that subgroup of patients with ASH referred to the National Heart and Lung Institute and diagnosed prior to the general availability of echocardiography. The clinical course of these patients was variable. Fourteen (40%) of the 35 patients improved or remained stable, including four patients who received propranolol. Ten (29%) of the 35 patients deteriorated clinically and 11 (31%) of the 35 patients died suddenly (4% mortality per year). Two of the patients who died suddenly had previously undergone operation (six and 13 years previously) with resultant abolition of the outflow gradient; four others were taking propranolol. Neither symptomatology, electrocardiographic abnormalities, heart size, left ventricular ejection or upstroke time, magnitude of outflow gradient, or left ventricular enddiastolic pressure proved predictive of sudden death. Excluding patients who had previous operation, eight (40%) of 20 patients with obstruction who were followed long term and one (9%) of patients without outflow obstruction died suddenly. Thus, the clinical and hemodynamic spectrum of ASH in childhood is broad. However, deterioration in clinical condition or sudden death has been relatively common in children with overt signs of cardiac disease.

ISSN:0009-7322    

出版商:OVID    

年代:1976

数据来源: OVID

摘要:

Fifty-eight subjects with echocardiographic criteria for an abnormal septal to left ventricular posterior wall ratio were studied. Echocardiographic findings were related to clinical cardiac status. Abnormal ratios were found in normal children and in children with a variety of cardiac lesions, only one of which was obstructive or non-obstructive cardiomyopathy. In those without cardiomyopathy, the abnormal ratio usually resolved by one or two years of age. Persistence of abnormal ratio usually occurred in patients with increased right ventricular anterior wall thickness or idiopathic hypertrophic subaortic stenosis. The cause of abnormal ratio is multifactorial.

ISSN:0009-7322    

出版商:OVID    

年代:1976

数据来源: OVID

摘要:

Overdrive atrial stimulation was performed in 20 electrophysiologically normal children at the time of routine diagnostic cardiac catheterization, for the determination of the sinus node recovery time (SNRT). Measurements were made at pacing rates of 120, 150, 180, and 200 beats/min.The absolute recovery times demonstrated a wide range of values (420–1280 msec). Expressed as a percent of the resting P-P interval, values at pacing rates of 120 and 150 beats/min were 109–166%, with significantly less overdrive suppression (P< 0.001) occurring at the two faster pacing rates. Atropine diminished the maximum SNRT in all patients tested. This study reports normal values for the SNRT in children. Factors which influence the SNRT are the resting heart rate, the rate of overdrive, and the autonomic tone. In children, the sinus node recovery time should be expressed in terms of the resting sinus interval

ISSN:0009-7322    

出版商:OVID    

年代:1976

数据来源: OVID

摘要:

His bundle recordings were studied in four patients with short P-R and A-H intervals, and narrow QRS complexes, who had experienced several episodes of supraventricular tachyarrhythmias. The heart was paced from the high right atrium (HRA) and the coronary sinus (CS). In three patients the A-H Wenckebach phenomenon occurred at higher rates (greater than 200 pacing beats/min) when the CS was paced than when pacing was performed from the HRA. Moreover, CS stimulation produced smaller increments in the A-H interval than did pacing from HRA. The extrastimulus method of testing was done. In cases 1 and 2 the functional refractory period of the A-H tissues was 15 to 25 msec shorter during CS pacing than when pacing from the HRA. In case 3, the low right atrium (LRA) as well as the other two sites were paced. A type I gap was seen from HRA, a type 2 gap from CS, and both types appeared when the LRA was paced. Case 4, in which the mid-right atrium (MRA) was also stimulated, had a double pathway from HRA and CS with conduction through the accessory pathway late in the cycle and through the A-V node earlier in the cycle. However, the A-V node could not be penetrated during MRA stimulation. It appeared that the pacing site influenced the A-H conduction pattern and refractoriness, possibly by changing the site and/or mode of entry of the stimulus into the pathways that are responsible for this syndrome.

ISSN:0009-7322    

出版商:OVID    

年代:1976

数据来源: OVID

摘要:

Frank lead ECG/VCG changes with deep inspiration, expiration, and body position were investigated in 194 patients, 100 with an old myocardial infarction and the remaining 94 chosen as a representative sample of catheterization laboratory patients with a variety of cardiac conditions. In a subgroup of 144 of the patients, Frank lead records were made both at the fifth and the fourth intercostal space. Diagnostic interpretation was performed using the VA-Pipberger ECG Program.The results indicate that, in general, body position and electrode level influence on mean intervals and orientation angles is negligible. There was a highly significant decrease in the R and Q wave amplitudes in leads X and Z and in the maximum spatial magnitude of QRS when electrodes were shifted from the fifth to the fourth interspace. The most pronounced decrease in ECG/VCG amplitudes took place in deep inspiration while mean orientation angles changed little, with the exception of QRS elevation. However, while mean changes with body position and electrode level were rather small, substantial orientation and magnitude changes took place in many patients. Diagnostic interpretation of the records changed in 12.5% with electrode level change, in 11.9% with the transition of body position, and in 16.8% with deep inspiration. Strict standardization of electrode positions and recording procedure is suggested, particularly when serial comparison of Frank lead records is planned.

ISSN:0009-7322    

出版商:OVID    

年代:1976

数据来源: OVID

摘要:

Although prolonged infra-His conduction time in bifascicular block is suspected of denoting trifascicular disease, adequate documentation is lacking concerning the correlation between lengthened His-Q interval (H-Q) and the risk of development of complete heart block (CHB). H-Q in conducted sinus beats in patients with bifascicular block associated with Mobitz II or intermittent CHB represents the approximation of maximal H-Q prolongation prior to onset of trifascicular block. To assess this relationship between prolongation of H-Q and trifascicular block, His bundle electrocardiography (HBE) was performed in 50 patients with chronic bifascicular block exhibiting Mobitz II block or transient CHB. Mobitz II or episodic CHB was shown in all patients: within two days prior to HBE in 45/50 patients; in 39/50 patients during HBE; and following HBE in five patients. In 49/50 patients H-Q was prolonged (greater than 55 msec) and in 47 this interval was substantially lengthened (65 msec or greater). Since marked H-Q prolongation in conducted sinus beats was documented in nearly all patients with bifascicular block associated with intermittent complete trifascicular block, we conclude that a considerably lengthened H-Q interval in bifascicular block is not only a usual prerequisite, but also strong evidence, for impending complete heart block.

ISSN:0009-7322    

出版商:OVID    

年代:1976

数据来源: OVID

摘要:

In 12 anesthetized open-chest dogs, ventricular epicardial activation maps were constructed and electrograms were recorded from the bundle of His, left bundle branch, and subendocardial Purkinje fibers 24 hours following Harris 2-stage ligation of the left anterior descending coronary artery. All animals developed ectopic ventricular depolarizations and/or ventricular tachycardia. The earliest area of epicardial activation was located along the border of the infarct in the left ventricle in all animals. Bipolar recording from various levels of the conduction system and ventricular myocardium revealed that the earliest recorded electrical activity originated in subendocardial Purkinje fibers which had survived the acute myocardial infarction. The origin of these arrhythmias was further studied by pacing through the electrode which had recorded the early Purkinje activity and comparing the surface ECG and activation sequence with that of the spontaneous rhythm. These data tend to support the hypothesis that ventricular arrhythmias occurring 24–72 hours following acute myocardial infarction have their origin in the subendocardial Purkinje network which has survived the infarction.

ISSN:0009-7322    

出版商:OVID    

年代:1976

数据来源: OVID

摘要:

Sixteen patients aged between one day to 18 years with Ebstein's malformation of the tricuspid valve were studied with ultrasound. The findings were compared with a group of 74 patients without Ebstein's malformation. Two features were considered specific for Ebstein's malformation: 1) ability to record the anterior tricuspid leaflet (ATL) farther to the left of the left sternal border than in the control group; and 2) abnormally prolonged interval between the “C” points of the tricuspid and the mitral valve echoes (M, T, I). All other parameters measured were nonspecific for Ebstein's anomaly of the tricuspid valve. The sail sound was recorded in ten patients with Ebstein's malformation and occurred at the time when the anterior tricuspid leaflet was in the most posterior position.In a patient with congenital heart disease, an M, T, interval greater than 0.03 sec and recording of an anterior tricuspid leaflet near the apex of the heart strongly suggest the diagnosis of Ebstein's malformation. These two criteria were not fulfilled in any patient who did not have Ebstein's malformation. Conversely, however, absence of these two features does not rule out Ebstein's anomaly of the tricuspid valve.

ISSN:0009-7322    

出版商:OVID    

年代:1976

数据来源: OVID