The locus of a novel gene responsible for arrhythmogenic right-ventricular dysplasia characterized by early onset and high penetrance maps to chromosome 10p12-p14.

Arrhythmogenic right-ventricular dysplasia (ARVD), a cardiomyopathy inherited as an autosomal-dominant disease, is characterized by fibro-fatty infiltration of the right-ventricular myocardium. Four loci for ARVD have been mapped in the Italian population, and recently the first locus was mapped in inhabitants of North America. None of the genes have been identified. We have now identified another North American family with early onset of ARVD and high penetrance. All of the children with the disease haplotype had pathological or clinical evidence of the disease at age <10 years. The family spans five generations, having 10 living and 2 dead affected individuals, with ARVD segregating as an autosomal-dominant disorder. Genetic linkage analysis excluded known loci, and a novel locus was identified on chromosome 10p12-p14. A peak two-point LOD score of 3.92 was obtained with marker D10S1664, at a recombination fraction of 0. Additional genotyping and haplotype analysis identified a shared region of 10.6 cM between marker D10S547 and D10S1653. Thus, a novel gene responsible for ARVD resides on the short arm of chromosome 10. This disease is intriguing, since it initiates exclusively in the right ventricle and exhibits pathological features of apoptosis. Chromosomal localization of the ARVD gene is the first step in identification of the genetic defect and the unraveling of the molecular basis responsible for the pathogenesis of the disease.

Hepatic vein to the azygous vein anastomosis for pulmonary arteriovenous fistulae.

Pulmonary arteriovenous fistulae after a cavopulmonary anastomosis have been reported to resolve after hepatic venous return is included in the pulmonary circulation. We report a case in which the hepatic veins were redirected to the pulmonary circulation by connecting them directly to the azygous continuation of the inferior vena cava that had previously been connected to the right pulmonary artery. The patient's arterial saturation of 71% increased to 92% after 6 months.

Right bundle branch block: a source of error in the Doppler assessment of right ventricular pressure in patients with a ventricular septal defect.

A case is presented in which low right ventricular pressure was calculated erroneously from the Doppler-derived velocity of flow through a ventricular septal defect. This is thought to be due to the presence of right bundle branch block. Reasons for this error and a way to avoid errors in calculation are discussed.

Auscultation of the heart: a trial of classroom teaching versus computer-based independent learning.

Declining skills in auscultation of the heart prompted an evaluation of teaching methods for medical students. A comparison of classroom teaching and computer-aided independent learning of auscultation was carried out with two groups of approximately 20 second-year medical students. Both groups used approximately 20 recorded normal and abnormal heart sounds and murmurs, chosen to illustrate learning issues. For the classroom group a cardiologist presented each case through multiple stethophones and led the discussion. The individual study group used a new CD-ROM collection of cases and recordings in quiz format, with a hypertext link to a comprehensive text on auscultation and additional recordings. Students were tested with 16 multiple choice and 5 open questions on eight selected recordings, and evaluated the teaching by questionnaire. The classroom-taught students scored higher on open questions than the CD-ROM-taught group, but in general performance by both groups was satisfactory and equivalent. Students of both groups repeatedly had difficulty classifying regurgitant and ejection murmurs and identifying characteristics of the second heart sound. Both CD-ROM and classroom teaching methods were highly rated by students but most students preferred a combination.

Paediatric echocardiography by telemedicine--nine years' experience.

In 1987 we established a realtime echocardiography service by telemedicine from the paediatric cardiology department of a tertiary-care hospital in Halifax. The service was initially provided to single regional hospital but was expanded to six regional hospitals in the three Canadian Maritime Provinces. The system used a dial-up broadband video-transmission service provided by the telephone companies. Records of all transmissions were kept prospectively and reviewed to January 1997. A total of 324 transmissions were made. During 1995-96 there were 135 studies: 69 (51%) were urgent examinations of newborn children and 30 (22%) were urgent examinations of older children; repeat studies and postoperative checks (usually for pericardial effusion) accounted for the other 36 studies (27%). The images were of broadcast quality except in five cases where problems with transmission or poor sedation occurred. A comparison of 26 transmitted studies with repeat, 'in person' studies showed no important discrepancies in diagnosis. During the two-year study period, the cost of the network (equipment leasing costs and telecommunications costs) was C$90,000. Use of the telemedicine network saved unnecessary patient transfer in 31 cases. The cost of the transportation avoided was C$100,000-C$118,000. This review confirms our preliminary findings that broadband echocardiography transmission provides a service comparable in availability and accuracy to that provided in our paediatric cardiology division.

Transvenous closure of patent ductus arteriosus in a sick 2780g infant.

A three-and-a-half-month-old 2780 g critically ill infant had successful transvenous coil occlusion of a ductus arteriosus. At six-and-a-half months of age the infant died, and autopsy showed coverage of the coil on the aortic aspect and no lumenal narrowing. It was concluded that transvenous coil occlusion of the patent ductus arteriosus in small infants is possible and that th venous route is preferred to be arterial route.

Familial coarctation of the aortic arch with bilateral ptosis: a new syndrome?

A Newfoundland family with the apparently unique syndrome of complex coarctation of the aortic arch, bilateral stenoses of the subclavian arteries, bilateral ptosis, sensorineural deafness, and bronchial asthma is reported. This syndrome appears to have affected at least four generations, and has the characteristics of autosomal dominant inheritance.

Echocardiography of intracardiac filling defects in infants and children.

Intracardiac masses are rare in infants and children. Early detection is essential to their successful management. We present seven patients in whom echocardiography established the diagnosis and was crucial in the management. Three of the masses were primary cardiac tumors and four were thrombi. Patient 1: an infant with a calcified left ventricular fibroma. Patient 2: a neonate who presented with cyanosis due to obstruction of the right ventricular inflow tract by a fibroblastic tumor. Patient 3: an infant with a right atrial myxoma presenting as sepsis. Patient 4: a child who had a pulmonary embolus after a pulmonary valvotomy and was found to have a right ventricular thrombus. Patient 5: a child with a right atrial thrombus following a Fontan procedure for univentricular atrioventricular connection. Patient 6: a child with a left ventricular thrombus due to a dilated cardiomyopathy in association with epidermolysis bullosa. Patient 7: An infant with bilateral lobar emphysema, an aorticopulmonary window with left ventricular fibroelastosis, who developed a left ventricular thrombus.

Friedreich's ataxia presenting as cardiac disease.

Three male children with Friedreich's ataxia, from a single family, are described. The first patient presented as a cardiologic problem with anginalike chest pain. He was found to have echocardiographic evidence of concentric left ventricular hypertrophy (LVH). He later developed ataxia. The younger brother also had LVH but was asymptomatic and later became ataxic. The elder brother was already ataxic at the time of diagnosis. To our knowledge this is the first report of echocardiographic concentric left ventricular hypertrophy preceding the neurologic syndrome of Friedreich's ataxia.

Left-axis deviation in otherwise healthy children.

Eighteen children with left-axis deviation on the electrocardiogram but no other detected abnormalities are reported. The implications of this finding are discussed. No untoward cardiovascular events occurred during the period of follow-up and the electrocardiographic findings remained unchanged. This, therefore, appears to be a benign entity in the short term but longer follow-up is required before the ultimate prognosis can be determined.

Antibodies to heated milk protein in coronary heart disease.

Coronary arteriography was used to identify 37 patients with triple coronary vessel disease and 37 patients with no evidence of occlusive coronary atheroma. Two techniques were used to analyse serum levels of antibodies to heated milk protein, passive haemagglutination and enzyme-linked immunosorbent assay. No significant differences in these antibodies were observed between triple and zero vessel disease patients. Even after applying ECG evidence of myocardial infarction as a further criterion for classifying patients, no evidence was obtained to support the hypothesis that serum antibodies to heated milk protein are elevated in coronary heart disease.

The effect of various background protocols on the measurement of left ventricular ejection fraction in equilibrium radionuclide angiography.

Four methods of calculating left ventricular ejection fraction from equilibrium radionuclide angiography have been assessed for inter-observer variability and compared to single-plane contrast cineangiography. The superiority of data-processing methods which use a left ventricular region of interest which follows the changing size of the left ventricle into systole is demonstrated. A simple method of correcting for background is suggested as an alternative for those centres not possessing the necessary software for methods involving a changing region of interest.

Calcified left atrial myxoma with floppy mitral valve.

A heavily calcified left atrial myxoma in a man aged 53 was diagnosed from the plain chest x-ray film and confirmed by echocardiography. There was also moderate mitral regurgitation caused by a floppy mitral valve. Before a systemic embolus is considered to have arisen from a floppy mitral valve, echocardiography must be performed.

Persistence and effects of sinus rhythm after Fontan procedure for tricuspid atresia.

Four patients who had had a Fontan type of procedure for tricuspid atresia 23, 6, 6, and 11 months previously were investigated by ambulatory electrocardiographic recording and simultaneous recording of the jugular venous pressure and echocardiogram of the conduit or pulmonary valve. All had been considerably improved by the operation. In 1 patient episodes of supraventricular tachycardia were recorded but no rhythm disturbance was detected in the other 3. Pulmonary blood flow was shown to be pulsatile and atrial systole is an important factor in this. The conduit valve showed delayed opening and slow closure suggesting that its presence in the pulmonary circuit may be unnecessary.

Aortic arch interruption presenting with absence of all limb pulses.

Three patients with aortic arch anomalies presented with severe heart failure, acidaemia, and poor or absent upper and lower limb pulses. Prominent carotid arterial pulsations were detected which distinguished the condition clinically from aortic atresia. In 2 patients with a left aortic arch, interruption was distal to the left common carotid artery and there was an aberrant right subclavian. In the 3rd patient with a right aortic arch, interruption was distal to the right common carotid and there was an aberrant left subclavian artery. By dilating the narrowed ductus, prostaglandin E2 infusion corrected the acidosis. Successful surgical correction was achieved in one patient by direct anastomosis of descending aorta to ascending aorta and the base of the left common carotid artery.

Correction of anomalous origin of left coronary artery using left subclavian artery.

A case of anomalous origin of the left coronary artery from the pulmonary artery is reported in which surgical correction by anastomosis of the left subclavian artery to the left coronary artery was performed at the age of 6 months. There was a dramatic clinical improvement, and at 22 months repeat angiocardiography disclosed a patent graft and remarkable improvement in left ventricular function. It is recommended that this is the operation of choice for infants in whom cardiac catheterisation fails to show a shunt into the pulmonary artery or the shunt is small.

Cardiac abnormality in polymyositis.

Thirteen patients with polymyositis were investigated for the presence of cardiac disease by clinical examination, chest x-ray, electrocardiogram, and systolic time intervals. 5 patients had evidence of cardiac involvement. Compared with the other 8 patients, their polymyositis was more long-standing, more severe, and had remained active. Electrocardiogram usually showed arrhythmias and conduction disturbances, and 4 of the 5 patients had abnormal systolic time intervals indicating left ventricular dysfunction. Left ventricular involvement in polymyositis is more frequent than previously recognized and systolic time intervals are a simple, noninvasive method of detecting this.