Subaortic stenosis: An unrecognized problem in transposition of the great arteries

Right ventricular (subaortic) obstruction has only rarely been described in complete transposition of the great arteries. Five patients with complete transposition of the great arteries in whom subaortic stenosis was angiocardiographically demonstrated were studied. All had a pressure gradient of 30 to 55 mm Hg across the aortic outflow tract. Two of the patients manifested mild tricuspid insufficiency, and another two had coarctation of the aorta. The etiologic, anatomic, hemodynamic and prognostic aspects of this unusual anomaly are discussed. An angiocardiographically demonstrated series of this anomaly has not been reported on before.     

Segmental study of the terminal coronary vessels in coarctation of the aorta: A natural model for study of the effect of coronary hypertension on human coronary circulation

An electron microscopic study of the coronary terminal circulation (starting with the small coronary arteries) was carried out on small pieces of myocardium operatively resected from the left ventricle in 11 patients with coarctation of the aorta. The patients were 4 to 20 years of age. Structural modifications were found in the small coronary arteries and arterioles. Two patterns of morphologic alterations were noted in these small resistance vessels. In the first pattern, seen in most of the children, the components of the arterial wall were still distinguishable, and well represented portions of smooth muscle layers were visualized together with muscle cells showing signs of degeneration and more or less widespread collagenous islets. The second pattern, seen in young adults, was characterized by a total collagenous transformation of the arterial wall. In contrast, the smaller microvessels (precapillary sphincters, metarterioles and capillaries) appeared free of pathologic change. It is postulated that the precapillary sphincters play a special protecting and regulating role in the coronary microcirculation in such cases with elevated coronary pressure. It is suggested that surgery should be performed at an early age to prevent further development of structural changes in the microvessels. The microcirculatory damage may contribute to the increased surgical mortality in patients with coarctation of the aorta operated on at a later age. These findings should trigger further research on the small coronary vessels in systemic hypertension.     

Two-dimensional echocardiography in discrete subaortic stenosis

Thirty-seven patients with discrete subaortic stenosis (DSS) underwent 2-dimensional echocardiography (2-D echo) and cardiac catheterization. The peak systolic pressure gradients ranged from 0 to 150 mm Hg. Thirty-two patients had membranous DSS and 5 had fibromuscular DSS. Of 37 patients with DSS, 2-D echo diagnosed the presence and type in 35; in 2, a membrane was demonstrated by angiography. Of the 35 patients accurately diagnosed by 2-D echo, angiography corroborated the diagnosis in 33, but failed to show the membrane in 2. Subsequent cardiac surgery confirmed the accuracy of the echocardiographic diagnosis in these 2 patients. In all patients with membranous DSS, the anterior insertion of the membrane was demonstrated. In 9 of them the posterior insertion was demonstrated by tilt of the transducer but the anterior insertion disappeared. In 4 patients both insertions were demonstrated simultaneously and in 3 patients the membrane was demonstrated as a continuous line. In 4 of the 5 patients with fibromuscular DSS, both insertions of the lesion were demonstrated simultaneously. However, 2-D echo was unsuccessful in assessing the severity of obstruction. In only 1 patient did demonstration of the whole subaortic membrane as a continuous line below the aortic valve correlate with severe obstruction. Thus, the presence and type of DSS, but not the degree and severity, can be accurately and reliably diagnosed by means of 2-D echo.     

Transluminal carbon dioxide-laser catheter angioplasty for dissolution of atherosclerotic plaques

Carbon dioxide laser energy was used for the dissolution of atheromatous plaques. Flexible, nontoxic infrared optical fibers were used for the transmission of the carbon dioxide laser beam intraarterially. Dissolution of plaques and recanalization of obstructed arteries were achieved both in vitro and in vivo with controllable damage to the vessel walls.     

Pericardial effusion as the sole manifestation of infectious mononucleosis

A 56-year-old patient presented with fever, dyspnoea and large pericardial effusion, which were the only features of infectious mononucleosis. Atypical cases or infectious mononucleosis are common in older patients. Such a well documented case of effusive pericarditis, however, has not been previously recorded.     

Juxtaposition of atrial appendages: angiocardiographic observations

The angiographic features of four cases of left-sided juxtaposition and one case of right-sided juxtaposition of the atrial appendages are described. The anomalous appendage was cephalad and dorsal to the normal position of the left atrial appendage and was larger than normal during atrial diastole; the appendage located on the anatomically correct side was caudad and its diastolic size was less than normal. The four cases of left-sided juxtaposition were all associated with transposition of the great vessels. Right-sided juxtaposition was detected inadvertently in a patient with a congenital obstructive lesion of the mitral valve. Left-sided juxtaposition can be demonstrated angiocardiographically by opacification of the right atrium, whereas right-sided juxtaposition can be seen by contrast injection into any cardiac chamber but the left ventricle, with certain exceptions.     

From academics to practice

In about 80 percent of the cases of corrected transposition of the great arteries reported in the literature, other primary lesions, mainly ventricular septal defect and/or pulmonic stenosis were present, and the isolated lesion is only rarely found [1–3]. We studied 10 cases of corrected transposition of the great arteries without shunt or obstructive lesions.     

Intraventricular conduction disturbances: a review of prevalence, etiology, and progression for ten years within a stable population of Israeli adult males.

The ECG tracings of 5,204 working males aged 40 years and over, representing a random sample of Israeli civil service employees were reviewed, and 123 (2.36 per cent) displaying intraventricular conduction disturbances (IVCD) in the form of left anterior hemiblock (LAH), RBBB, RBBB + LAH and LBBB, were followed for a period of 10 years (1963 to 1973). While these patients were slightly older than the population they were derived from (53.5 versus 4938 years average age), there was no significant difference in ages between the various types of IVCD, but there was a marked increase in the frequency of all IVCD with age. Left anterior hemiblock constituted the most frequent IVCD (1.42 per cent), being twice as frequent as RBBB (0.65 per cent). The prevalence of RBBB + LAH was 0.17 per cent (7 per cent of all IVCD). To the best of our knowledge, this is the first time that the frequency of this condition has been assessed in an unselected male population.The vast majority of these ECG changes seem to be acquired. Ischemic heart disease (IHD) constituted the most frequent associated condition for all types of IVCD (28 per cent), its prevalence being similar (21 to 28 per cent) in LAH, RBBB and RBBB + LAH, but much higher in patients with LBBB (five of six patients). Hypertension (HT), not associated with IHD, was present in 24 patients and constituted the next most frequent factor (20 per cent). No definite etiology could be demonstrated in the remaining 64 patients (52 per cent), except for five (4 per cent of all IVCD and 0.1 per cent of the population studied) who displayed progressive IVCD and were considered to represent examples of a degenerative disease of the conduction system (DDCS). The latter confirms that monofascicular blocks (MFB) may represent an initial stage of DDCS.From the ECG point of view, 14 per cent of cases with MFB showed progression to bifascicular block (BFB) or complete heart block (CHB) within 10 years, regardless of etiology. This was more frequent in RBBB than in LAH (22.5 per cent versus 9.5 per cent). From the clinical point of view, the natural history of IVCD in patients with IHD parallels the natural history and prognosis of this disease. In contrast, the prognosis of IVCD in patients with isolated HT, or in asymptomatic subjects, was more benign even in patients reaching the stage of CHB. The natural history of DDCS began as RBBB or LAH in middle age or earlier and progressed to CHB through the stage of BFB. This process may last from a few years to a few decades; LBBB seems to be rarely if ever encountered in its course.     

Exercise-induced left ventricular dysfunction in symptomatic and asymptomatic patients with aortic regurgitation: assessment with radionuclide cineangiography

In patients with aortic regurgitation,, left ventricular dysfunction at rest, which is associated with a poor long-term prognosis, often develops before severe symptoms. To determine whether evidence of left ventricular dysfunction could be detected before it appeared at rest, 43 patients with severe aortic regurgitation were studied using radionuclide cineangiography during exercise. In 30 normal subjects, left ventricular ejection fraction increased during exercise (57 +/- 1 percent [mean +/- standard error] at rest, 71 +/- 2 percent during exercise, P less than 0.001). In contrast, among 21 symptomatic patients, ejection fraction was normal at rest in 14 patients (average 47 +/- 2 percent) but normal during exercise in only one patient (average 38 +/- 2 percent, P less than 0.001). Ejection fraction was normal at rest in 21 of 22 asymptomatic patients (average 62 +/- 2 percent) but was normal during exercise in only 13 (average 57 +/- 3 percent, P less than 0.001). Thus, exericse-induced left ventricular dysfunction can precede symptoms and dysfunction at rest. Radionuclide assessment of left ventricular function during exercise may prove valuable in sequentially following the state of left ventricular function in patients before the onset of symptoms or of irreversible left ventricular failure.     

Wenckebach A-V block: a frequent feature following heavy physical training.

Among 126 top Israeli athletes, in whom an ECG was obtained during a random survey, 11 had first-degree heart block (P-R greater than or equal 0.21 sec.) and in three of them Wenckebach's phenomenon was found. The latter could be demonstrated only after 15 minutes' rest in a recumbent position and was abolished by sitting, standing, and the administration of atropine. This subjects with Wenckebach's phenomenon were followed for 6 years. The heart block was found to be present only during seasons of intensive training and could not be demonstrated a few weeks after the training was reduced in intensity or stopped. No heart disease or diminution of performance developed during 6 years of follow-up. Transient second-degree heart block in top athletes is probably much more frequent than hitherto suspected, but it can be demonstrated only if the athlete is examined during rest and in the recumbent position. It is assumed to be a physiological phenomenon related to heavy physical training.