Intra-His bundle block complicating acute inferior myocardial infarction.

The unexpected findings of atrioventricular block or delay in the His bundle and proximal branches are described in a 51-year-old man with acute inferior myocardial infarction with narrow QRS complexes. With the information from the His bundle electrogram, the site of atrioventricular block is precisely localized.

Permanent pacemaker implantation in infants, children, and adolescents. Long-term follow-up.

Twenty-four patients in the pediatric age range who underwent implantation of a cardiac pacemaker for treatment of complete atrioventricular (A-V) block were followed for an average of five years (range 1-12 years). The etiology of the A-V block was surgical in 13 cases, congenital in nine, and acquired in two. Twenty patients had symptoms of cerebrovascular insufficiency and four had congestive heart failure. To date, 18 of the 24 patients studied are alive and well. Death occurred in six patients, five of whom had complex congenital heart defects, and one of whom had Refsum's disease. Death probably was caused by complete heart block despite pacemaker treatment in four patients, and congestive heart failure in two. In 18 of the 24 children with disabling complete A-V block, pacemaker therapy provided relief of symptoms and prolonged life.

Surgical repair of atrial septal defect in patients over 60 years of age. Long-term results.

In order to evaluate results of surgical repair of secundum atrial septal defect (ASD) in patients 60 years of age or older, a review was made of 16 patients who had undergone such operation between January 1964 and December 1974. Before operation eight patients were in functional classification III (New York Heart Association), seven were in class II, and one was in class I. Twelve patients had a left-to-right shunt greater than 3:1. Pulmonary artery systolic pressure was greater than 40 mm Hg in 12 patients and greater than 60 mm Hg in five. Four patients had documented paradoxical emboli and were being treated with Coumadin. Before operation all patients but one were receiving digoxin. Repair was accomplished by direct suture in two patients and Dacron patch graft in 14. No deaths occurred during the postoperative period. Postoperatively, ten patients were in class I, five in class II, and one remained in class III. The hospital stay ranged from eight to 20 days (average 11 days). Two patients died one year and another (at the age of 77) five years after surgery. The remaining 13 patients are alive and well three months to 11 years after surgery. We conclude that repair of secundum ASD in patients over the age of 60 is safe, has low morbidity, and produces considerable clinical improvement.

Unilateral pulmonary vein atresia: Diagnosis and treatment.

The clinical, hemodynamic, angiographic and pathologic features of unilateral pulmonary vein atresia in a 16 month old boy are described. The relevant findings were symptoms and signs of influenza, roentgenographic evidence of unilateral diffuse interstitial edema, prominent interlobar fissures and pleural effusion, absence of abnormal cardiac structure and prominent unilateral bronchial circulation. Angiocardiography was necessary for a definitive diagnosis and revealed the lack of a site of entry for venous blood from the right lung into the circulation. The patient was treated successfully by a right pneumonectomy. The histologic hallmark in this case was extensive intimal fibrosis of the pulmonary veins.

Congenital and surgical atrioventricular block within the His bundle.

In three patients with congenital heart disease the site of atrioventricular (A-V) block was localized within the His bundle with the aid of His bundle electrograms. In one patient with first degree A-V block and normal QRS configuration, electrophysiologic studies revealed "split" His potentials. The other two patients had complete A-V block, and their His bundle electrograms revealed His spikes both proximal and distal to the site of block. One of the two patients, who had a pattern of left bundle branch block in the electrocardiogram, had surgically induced complete A-V block after repair of an ostium primum atrial septal defect. The other patient with congenital A-V block had a narrow QRS complex and, in addition to complete block within the His bundle, prolonged A-V nodal conduction time but no associated cardiac anomaly. Both patients with complete heart block required pacemaker insertion. The natural history of intra-H-is bundle block is not known, and it is difficult to recommend appropriate therapy. More electrophysiologic studies are needed in patients with A-V block to determine the prognostic significance of such block or conduction delay in the His bundle.

Surgical experience in patients with Marfan's syndrome, ascending aortic aneurysm and aortic regurgitation.

Surgical treatment of cardiovascular complications in patients with Marfan's syndrome is usually recommended with apprehension since the systemic nature of the disease predisposes to early and late complications. To define the incidence of these complications, 30 patients were evaluated after surgical treatment of aortic insufficiency and ascending aortic aneurysm at the Texas Heart Institute. To provide a minimal follow-up period of 5 years, only patients operated upon during of before 1968 were included in this series. There were 9 female and 21 male patients aged 4 to 80 years (mean 44 years). Aortic insufficiency was treated by valvuloplasty in 3 patients and by aortic valve replacement in 27. Graft replacement of the ascending aorta was required in 23 patients, and the aneurysm was excised and the aorta repaired by direct anastomosis in 7. Two patients were lost to follow-up study; 12 of the remaining 28 (42.8 percent) lived 5 years or more. The hospital mortality rate was 20 percent (6 of 30); the causes of death included dissection or rupture of the aorta in three patients, congestive heart failure in two and pulmonary embolism in one. The 24 survivors lived from 5 weeks to 9 years. Follow-up data were available on 22 of these patients. Ten of these (45.4 percent) died of late complications. Seven died suddenly, four of these had redissection, one patient had occlusion of the right coronary artery, and two had ventricular fibrillation of no apparent cause. The remaining three died of noncardiac causes. Although the risk of ascending aortic and aortic valve surgery in patients with Marfan's syndrome is high, 42.8 percent of the patients in our series survived 5 years or more. We believe that surgery should be recommended for patients with Marfan's disease who have dissection of the aorta or severe aortic regurgitation, or both.

Supravalvular aortic stenosis. Echocardiographic features.

The echocardiographic manifestations of segmental supravalvular aortic stenosis are described in 2 patients. The diagnosis was confirmed by cardiac catheterization in both and at operation in 1. A systematic echocardiographic approach to such patients is described. The characteristic finding in these patients was the narrowing of the diameter of the aortic lumen at the stenotic area just distal to the aortic valve. As the transducer sweeps further cephalad the aortic lumen widens to a normal diameter. In one patient treated surgically, postoperative echogram demonstrated the narrowing to be reduced.

Concealed his bundle extrasystoles in congenital heart disease.

His bundle electrograms were recorded in two children with cardiac conduction disturbances. In the surface electrocardiograms of one patient His bundle extrasystoles mimicked atrial nonconducted bigeminal rhythms; in the other, they simulated second degree atrioventricular (A-V) block and conducted junctional extrasystoles. In both instances the conduction disturbance was a result of concealed conduction of the His bundle extrasystole into the A-V junction. We conclude that the surface electrocardiogram is suggestive but not definitive in diagnosing His bundle extrasystoles and that His bundle recordings are indispensable for correct diagnosis and treatment.

Treadmill exercise testing in the presence of digitals therapy or nonspecific ST-T changes: correlation with coronary angiography.

Treadmill exercise test results were studied in 93 patients with chest pain who had received digitalis therapy or had nonspecific ST-T changes in the resting electrocardiogram. Results of the treadmill test were correlated with the findings of coronary angiography. A positive treadmill result was defined as horizontal or down-sloping ST segment depression greater than or equal to 1.0 mm. Of the 40 patients with no or insignificant coronary artery disease, 15 had taken digitalis; 4 of the 15 demonstrated a positive response on the treadmill test. Of the 53 patients with coronary artery disease, 21 had taken digitalis; 15 of the 21 displayed a positive response. Among the remaining 32 not on digitalis, 20 had a positive response. The specificity of the treadmill exercise test was 96% in patients with coronary artery disease not on digitalis and whose resting electrocardiogram showed nonspecific ST changes. The specificity of the treadmill test in patients who had received digitalis was 73%. Sensitivity was 63% and 71%, respectively. By utilizing more stringent criteria in the interpretation of the treadmill exercise test (greater than or equal to 1.5 mm ST depression), among the patients on digitalis only 6.7% (1/15) with normal coronary arteries and 48% (10/21) with coronary artery disease had a positive response. With the use of the latter criterion the test was specific in 93% (14/15) of the patients and is usually indicative of coronary artery disease.