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J H McAnulty

Publications and source records attributed to J H McAnulty.

17 recordsLinked to original sources
PubMed1992

Analysis of local electrogram characteristics correlated with successful radiofrequency catheter ablation of accessory atrioventricular pathways.

UNLABELLED: Due to the limited myocardial lesions produced by radiofrequency current, the ablation of accessory pathways (AP) requires precise localization of such connections. The purpose of this study was to ascertain which characteristic(s) of the local bipolar electrogram, recorded from the ablation and adjacent electrode immediately prior to the application of radiofrequency current, correlated with precision in localization adequate to permit AP ablation. Signal analysis was performed for 326 sets of electrograms preceding the attempted ablation of 107 APs in 100 consecutive patients. For 80 antegrade APs, the following variables were evaluated: (1) the presence or absence of an AP potential; (2) the local atrial-AP interval; (3) the local atrioventricular (AV) interval; and (4) the relationship between the onset of local ventricular depolarization and onset of delta wave of the surface electrocardiogram. For the 27 concealed APs, the following characteristics were evaluated: (1) the presence or absence of an AP potential; and (2) the local VA interval during reciprocating tachycardia or ventricular pacing. RESULTS: Antegrade APs: By statistical analysis, the best correlate of successful ablation of an antegrade AP was a local AV interval less than or equal to 40 msec (positive predictive value = 94%; 95% confidence intervals [CI] = 81%-100%). Local AV intervals less than or equal to 50 msec preceded 88% of successful AP ablations, compared to only 8% of failed radiofrequency current applications. The positive predictive value of the other variables were: presence of an AP potential: 35% (95% CI = 27%-40%); local atrial-AP intervals less than or equal to 40 msec: 54% (95% CI = 43%-66%); and local ventricular depolarization preceding onset of the delta wave 43% (95% CI = 34%-52%). For concealed APs, the positive predictive value of a VA interval less than 60 msec was 71% (95% CI = 48%-88%); the positive predictive value for the presence of an AP potential was 58% (95% CI = 32%-81%). CONCLUSIONS: No single electrogram characteristic had a positive predictive value and a sensitivity greater than 90% for AP localization adequate for radiofrequency current ablation. For antegrade APs, the best correlate of adequate localization was a local AV interval less than or equal to 40 msec; as a corollary, radiofrequency current applications at sites where the local AV was greater than 60 msec, were unlikely to be effective. Objective criteria for the localization of concealed APs were less certain. Electrogram analysis, as a guide to AP localization and ablation, requires careful analysis of multiple variables, with analysis of the local AV interval a salient objective factor.

Adult↗
PubMed1979

Alternating atrial and ventricular tachycardia.

A patient with alternating atrial and ventricular tachycardia is described. He had an acute myocardial infarction and was taking digitalis. The atrial tachycardia, which was occasionally associated with aberrant ventricular conduction, was able to interrupt the ventricular tachycardia though the reverse was not true, suggesting a retrograde conduction block. This patient shows that atrial and ventricular arrhythmias can alternate and, since tachycardia with aberrant ventricular conduction can closely resemble ventricular tachycardia, intra-atrial electrocardiography may be necessary to establish an accurate diagnosis.

Digoxin↗
PubMed1979

Prospective evaluation of intrahisian conduction delay.

We prospectively evaluated 46 patients who had intrahisian conduction delay. Twenty-three had a split His potential and 23 had a prolonged HV interval with a normal QRS complex. In those with a split His, the interval between the two His potentials averaged 32.7 msec (range 9--90 msec); in nine patients this split His was demonstrated only by atrial pacing. The 20 patients from this group with 1:1 atrioventricular conduction have been followed for an average of 18.1 months (range 2--48 months). All are alive. Three have had syncope, but Holter monitoring revealed no bradyarrhythmias. In the 23 patients with a narrow QRS and prolonged HV interval, the HV interval averaged 73.7 msec (range 57--180 msec). Twelve of these patients received pacemakers at the time of the His bundle study, six had symptomatic atrioventricular block and five had symptomatic sinus pauses. The 11 patients who did not receive pacemakers have been followed for an average of 15.1 months (range 2--44 months). In three with recurrent syncope and five with dizziness, monitoring has revealed no bradyarrhythmias. One patient died from a myocardial infarction without arrhythmias. Further prospective evaluation of patients with intrahisian conduction delay without documented bradyarrhythmias is needed, but with follow-up averaging 17 months and up to 4 years, patients with intrahisian conduction delay and without documented bradyarrhythmias appear not to require prophylactic permanent pacemakers to decrease morbidity or mortality.

Adult↗
PubMed1978

A prospective study of sudden death in "high-risk" bundle-branch block.

We prospectively followed 257 patients with bifascicular and trifascicular conduction-system disease and intact atrioventricular conduction who had undergone His-bundle studies. Forty-seven per cent had associated coronary-artery disease, and 23 per cent primary conduction-system disease. His-ventricular interval was moderately prolonged in 43 per cent and markedly prolonged in 12 per cent. During an average follow-up period of 25 months 50 patients died. However, death was sudden in only 27, and 17 of the sudden deaths were not due to bradyarrhythias. Actuarial analysis showed an overall mortality rate (mean +/- S.E.) of 19 +/- 2.6 per cent at two years, mortality from sudden death being 10 +/- 2.6 per cent. Permanent heart block occurred in 12. No clinical symptoms (including syncope), electrocardiographic findings, electrophysiologic data or their combination identified patients at high risk of sudden death. Sudden death due to bradyarrhythmia is uncommon in patients with bundle-branch block and intact atrioventricular conduction. Therefore, routine prophylactic use of permanent pacemakers in all such patients is inappropriate. Pacemaker implantation should be reserved for those with documented symptomatic bradyarrhythmias.

Adult↗
PubMed1978

Antibiotic prophylaxis in patients with rheumatic heart disease and prosthetic devices.

Prophylaxis is defined as: "measures designed to preserve health and prevent the spread of disease" (18). Two implicit parts to such a definition are first, that what is being prevented causes disease, and second, that the measure(s) proposed prevents this disease. We will briefly review the evidence that patients with rheumatic heart disease and/or prosthetic cardiac devices are at increased risk of morbidity and mortality from infection and further that antibiotics reduce this morbidity and mortality. Antibiotic prophylaxis is undertaken in patients with rheumatic heart disease and in those with prosthetic devices for two purposes: 1. prevention of reccurrences of rheumatic fever; and, 2. prevention of infective endocarditis. These are two different issues which will be discussed separately.

Anti-Bacterial Agents↗
PubMed1978

Characterisation of heart rate response to exercise in the sick sinus syndrome.

Patients with sick sinus syndrome have abnormalities of the sinoatrial node. We have measured the heart rate response to exercise in 7 patients with sick sinus syndrome without significant associated heart disease (group A) mean age 53.4 years, and compared this with 7 'normal' patients who were age-matched to within 5 years (group B), and 7 younger, well-trained subjects (group C). All underwent maximal treadmill exercise. Although maximum oxygen consumption (VO2max), 1/min per kg, in group A was not significantly different from group B (23.8 +/- 4.7 vs 19.9 +/- 0.8, mean +/- SE) maximum heart rate, beats/min, in group A was significantly lower than in group B (124 +/- 8.9 vs 163 +/- 3.7, P less than 0.001). At the end of 3 minutes of Bruce Stage I exercise, group A patients had a heart rate less than 130/minute (95% confidence level), whereas group B patients had heart rates greater than 134/minute. VO2 was plotted against heart rate (HR). Patients in group A had a significantly lower slope (deltaHR 5.20 +/- 0.33/delta1 ml VO2/kg per min, P less than 0.001). There was no significant difference in the slopes between groups A and C. On exercise patients with sick sinus syndrome have a normal VO2, but a reduced heart rate response as compared with age-matched normal patients. This abnormal heart rate response to the physiological stimulus of exercise may be of help in the evaluation of patients with sick sinus syndrome who do not have significant underlying heart disease.

Arrhythmia, Sinus↗
PubMed1978

Severe aortic stenosis with impaired left ventricular function and clinical heart failure: results of valve replacement.

Nineteen patients, aged 58-80 years, with severe isolated aortic valve stenosis, severely reduced ejection fraction and clinical heart failure underwent aortic valve replacement between January 1970 and April 1977. Ten had concomitant coronary artery disease (all underwent additional coronary bypass surgery), 17 had angina pectoris and four had syncope. Aortic valve area index was 0.32 +/- 0.03 cm2/m2 (mean +/- SEM); left ventricular (LV) end-diastolic volume index was 117 +/- 9 ml/m2 and LV ejection fraction was 0.37 +/- 0.02. There were four operative deaths and one late death. The follow-up time ranged from six to 74 months (38 +/- 6 months). Actuarially determined three-year survival is 74 +/- 10%; the expected five-year survival is the same. One patient had a serious cerebrovascular accident. Of the remaining survivors, seven were initially Functional Class IV and six Class III; currently, six are Class I and seven Class II (New York Heart Association classifications). The cardiothoracic ratio has decreased from 0.54 +/- 0.03 to 0.49 +/- 0.03. Repeat hemodynamic evaluation has been performed in 10 patients, 22 +/- 6 months after surgery. In these 10 patients, the aortic valve gradient decreased from 55 +/- 7 11 +/- 1.3 mm Hg; LV end-diastolic pressure from 22 +/- 2.4 to 9 +/- 1.9 mm Hg; LV end-diastolic volume index from 119 +/- 16 ml/m2 to 107 +/- 11 ml/m2. LV ejection fraction has increased dramatically from 0.34 +/- 0.03 to 0.63 +/- 0.05 and mean velocity of circumferential fiber shortening from 0.57 +/- 0.08 to 1.3 +/- 0.18 circ/sec. The encouraging long-term survival, improved functional class and the marked improvement in left ventricular function that occurred in our patients indicate that all patients with severe aortic stenosis in clinical heart failure should be offered aortic valve replacement.

Aged↗
PubMed1978

Survival in patients with intraventricular conduction defects.

All 42,000 electrocardiograms taken at the University of Oregon Health Sciences Center from 1969 through 1971 were reviewed; 325 patients (0.77%) had left bundle-branch block (LBBB) or right bundle-branch block (RBBB) with axis deviation (AD). In December 1974, 90% were contacted or found to be dead. The five-year survival rate (actuarial technique) (mean +/- SE) was 45.5 +/- 2.9%. It was significantly worse than that of age- and sex-matched "controls." In most patients the cause of death could not be determined. Survival of 164 LBBB patients (40.7 +/- 4.1%) at five years was not significantly worse than that of 161 RBBB and AD patients (49.5 +/- 4.2%). Those with syncope did no worse in terms of survival than did those without. The five-year survival in coronary artery disease patients was 33.7 +/- 4.4%, in those with primary conduction system disease (20% of patients), it was 50.6 +/- 6.6%. It will be necessary to know the causes of death and of syncope in conduction disease patients before it can be determined whether or not pacemakers can prevent either.

Adult↗
PubMed1975

Improvement in left ventricular wall motion following nitroglycerin.

Coronary artery disease patients frequently have left ventricular wall motion abnormalities. Though nitroglycerin is commonly used in ischemic heart disease, its effects on wall motion abnormalities is unknown. In this study we have evaluated the effects of nitroglycerin on wall motion abnormalities and on ejection fraction in 25 patients. Sixteen had coronary artery disease (greater than 70% luminal narrowing). Six had no evidence of heart disease and three had congestive cardiomyopathies with normal coronary arteries. Left ventricular angiography was performed prior to and six minutes after administration of 0.4 mg of sublingual nitroglycerin. Twelve of the 16 coronary artery disease patients had wall motion abnormalities, and in seven of these, segmental wall motion improved after nitroglycerin. In five, all motion did not change. The initial heart rate, left ventricular systolic and end-diastolic pressure, and left ventricular end-diastolic volumes were not different for those whose wall motion improved versus those whose did not. The increase in the former and fall in the latter three hemodynamic parameters were significant (P less than 0.01) and similar for the two groups. In those whose wall motion abnormalities improved after nitroglycerin, ejection fraction (mean plus or minus se) increased significantly (P less than 0.05), from 0.47 plus or minus 0.025 to 0.62 plus or minus 0.046. In those without improvement, the ejection fraction went from 0.55 plus or minus 0.056 to 0.58 plus or minus 0.051 (NS). Three patients with congestive cardiomyopathy showed no improvement in ventricular wall motion or ejection fraction after nitroglycerin. Left ventricular wall motion abnormalities and ejection fraction improved in some coronary artery disease patients following nitroglycerin. The mechanism for this is unknown; however, ventriculography before and after nitroglycerin may be of potential usefulness for identifying areas of reversible wall motion abnormalities.

Adult↗
PubMed1975

Diastolic murmurs in the presence of Starr-Edwards mitral prosthesis.

Diastolic murmurs associated with the Starr-Edwards mitral prosthesis have not been described previously. In this report, five patients with mitral prostheses are described in whom apical mid-diastolic and presystolic murmurs resulted from two different causes. Three patients had clots obstructing the prosthetic orifice. The other two had normally functioning protheses and moderately severe aortic insufficiency. The occurrence of mid-diastolic and presystolic murmurs in the presence of a normally functioning prosthetic mitral valve demonstrates that 1) the mid-diastolic Austin Flint murmur can occur in the absence of incomplete mitral valve opening, premature mitral valve closure, vibrating mitral leaflets, or relative mitral stenosis and 2) the presystolic Austin Flint murmur can occur in the absence of incomplete valve opening or presystolic mitral regurgitation. However, the presystolic murmur was associated with early closure movement of the presthetic poppet.

Adult↗