Thyrotoxicosis induced by amiodarone, a new efficient antiarrhythmic drug with high iodine content.

Amiodarone is an antiarrhythmic agent with high iodine content. Ten patients treated with amiodarone developed thyrotoxicosis. I131 uptakes were negligible, and TT3 levels low in relation to TT4 levels, and sometimes even normal. Cessation of amiodarone caused thyroid functions to return to normal in one to five months, unrelated to propylthiouracil treatment. Eight of the patients had normal thyroid glands on radioscan or palpation. All patients tested had normal TRH tests. Thyrotoxicosis is a relatively common complication of amiodarone treatment, probably caused by its high iodine content. It is possible in apparently normal thyroid glands, suggesting failure of the homeostatic mechanisms controlling thyroid synthesis and release in these patients. Amiodarone is very efficient in controlling tachyarrhythmias and angina pectoris, situations in which thyrotoxicosis is dangerous. Thyroid function tests should therefore be drawn periodically, and the complication considered whenever tachyarrhythmias worsen on treatment with amiodarone.

Atrioventricular block in situs ambiguus and left isomerism (polysplenia syndrome).

Three patients are described who had situs ambiguus and left isomerism (polysplenia syndrome) and advanced atrioventricular block. One presented with a complex bradyarrhythmia with Wenckebach block. The other two had congenital atrioventricular block with a narrow QRS at a ventricular rate of 80 per minute, an atrial rate of 150' per minute, and both had a P wave axis directed superiorly and to the right in one, and superiorly to the left in the other. This ECG pattern was not observed in more than 400 adult patients with complete A-V block treated in our service. It is our opinion that in infants and children with heart disease the presence of complete A-V block with narrow QRS and an unusual P waves axis directed superiorly is strongly suggestive of left isomerism. The incidence rate of complete A-V block in left isomerism is nearly twenty percent of the cases described.

Angiography of azygos continuation of inferior vena cava in situs ambiguus with left isomerism (polysplenia syndrome).

We have in our records 11 patients with situs ambiguus and left isomerism (polysplenia). Ten had an interruption of the inferior vena cava (IVC) with azygos continuation; in eight cases the continuation was to the left superior vena cava (LSVC), in one case to the right superior vena cava (RSVC) and in one case to both the LSVC and RSVC. Two patients underwent surgical correction by a baffle procedure of the functioning single atrium. The angiographic confirmation of the azygos system anatomy is important in planning the surgical correction of patients with left isomerism. Clinically, given the same heart defects with normal pressures, the right-sided drainage is probably more favorable, producing less peripheral desaturation.

Single arterial trunk arising from the aortic arch associated with coarctation of the aorta.

A 6-day-old baby with a single arterial trunk arising from the aortic arch is reported. The baby had coarctation of aorta with patent ductus arteriosus and ostium primum atrial septal defect. A review of the literature in English reveals no other case reported of an infant with this association of anomalies.

Congenital prolongation of Q-T interval: a family study of three generations.

Three generations of a family with the Romano-Ward syndrome are described. Of all the affected members, only 1 was symptomatic, experiencing episodes of syncope proven to be due to polymorphous ventricular tachycardia (PMVT) induced by chlorimipramine treatment for depression. During treatment of an episode of PMVT with lidocaine, the patient developed the 'torsade de pointes' variant of ventricular tachycardia, which progressed to ventricular fibrillation and was successfully treated with electroversion. The hazards of treating these patients with commonly used drugs, the possible etiologies for the Romano-Ward syndrome and its mode of inheritance are discussed.

Pregnancy in the presence of an implanted pacemaker.

Two young females, who had implanted pacemakers, and experienced an uneventful course of pregnancy and delivery are described. We suggest the chest wall under the breasts as the site of choice for the implanted unit in young females who might expect pregnancy. If this site is used, any restriction of the skin above the unit should be prevented as the abdomen and breasts increase in size. The problem of a fixed heart rate during the period of an increasing work load on the heart in pregnancy is discussed, and the use in these patients of an adjustable-rate pulse-generators is suggested.

The value of cardiac catheterization and cineangiography in infantile lobar emphysema.

Lobar emphysema is an uncommon cause of respiratory distress in infancy. Congenital heart disease is seen in about 20% of the patients with infantile (congenital) lobar emphysema. We described six infants with lobar emphysema. In three of them a congenital heart disease was demonstrated by cardiac catheterization and cineangiography; two had a tetralogy of Fallot with right aortic arch and the third infant a ventricular septal defect. The pulmonary angiography showed stretching of the arteries with very poor filling of the peripheral arteries and a characteristic smaller pulmonary vein in the affected lobe. In all the six patients the pulmonary artery pressure was normal. All the patients underwent lobectomy with good results. We feel that a preoperative cardiac catheterization and cineangiography is of value in this very sick group of infants.

Right aortic arch with isolation of the left subclavian artery.

A 5-year-old boy with cyanotic heart disease and weak pulses in the left arm is described. Cardiac catheterization and cineangiography confirmed the diagnosis of tetralogy of Fallot and right aortic arch with isolation of the left subclavian artery. In addition to the aortogram and right ventricular cineangiography, pulmonary angiography was performed, demonstrating that blood did not reach the left subclavian artery through a left ductus arteriosus.

Natural history of sick sinus syndrome following permanent pacemaker implantation.

Forty-four patients with sick sinue syndrome (SSS) who had been treated with a permanent pacemaker were followed for an average period of 39 months. Fifteen patients had bradyarrhythmia alone (group 1) and 29 had bradycardia-tachycardia syndrome (group 2). Eight patients, all from group 2, died within a short period following pacemaker implantation. They all had ischemic heart disease, congestive heart failure and a short history of the symptomatic dysrhythmia. Eleven patients developed stable chronic atrial fibrillation, which terminated the clinical syndrome. In the remaining 25 patients, all without evidence of ischemic heart disease, the dysrhythmia persisted although symptoms were successfully controlled following pacemaker therapy. Based on these observations and data obtained from other surveys, we delineated three courses of SSS: 1) a subacute course, characterized by a short-term survival; 2) a transient, self-limited course in which conversion to stable atrial fibrillation occurs; and 3) a chronic course, in which the dysrhythmia persists and permanent pacemaker therapy is indicated.

Complete heart block in an adult with corrected transposition of the great arteries treated with permanent pacemaker.

A 53-year-old patient with corrected transposition of the great arteries developed complete heart block with fainting episodes. After temporary pacing through the endocardium of the venous (anatomically left) ventricle, a permanent epicardial pacemaker was implanted. This case shows the progressive nature of the atrioventricular conduction disturbances, which are very common in association with this congenital cardiac anomaly.

The heart in acute glomerulonephritis: an echocardiographic study.

Patients with acute glomerulonephritis often are seen with signs suggesting heart failure. Whether these signs are due to fluid overload secondary to kidney damage only, or whether there is associated myocardial damage has not been elucidated. Fourteen children with acute glomerulonephritis were studied by echocardiography during the edematous phase of the disease and five months later to evaluate cardiac function in this disease. Left ventricular size and function remained normal in all children throughout the study. The most consistent finding was enlargement of the left atrium during the edematous phase with a return toward normal values five months later. There was no correlation between blood pressure and the echocardiographic findings. This study suggests that signs of heart failure in acute glomerulonephritis are not due to myocardial damage but probably reflect fluid overload.

Asplenia syndrome. Report of two cases.

Two babies with asplenia syndrome are described. Both presented with the severe cardiovascular anomalies found in this syndrome and had Howell-Jolly bodies in peripheral blood smears. The chest X-rays showed dextrocardia, decreased pulmonary circulation and a horizontal symmetrical liver, and were helpful in the clinical diagnosis. Additional findings at autopsy included a mobile cecum and bilateral trilobed lungs with bilateral eparterial bronchi.

Contribuiton of M-mode echocardiography to cardiac diagnosis. An assessment in 1,000 successive patients.

The contribution of M-mode echocardiography to cardiac diagnosis was evaluated in a series of 1,000 successive patients. Among subjects in whom a presumptive clinical diagnosis had been made, echocardiography demonstrated totally unexpected findings in 10 per cent, supported the clinical diagnosis in 50 per cent and was entirely within normal limits in 19 per cent. Among patients with evidence of heart disease but no firm clinical diagnosis, echocardiography established the diagnosis in 23 per cent, including 20 per cent of all patients referred for evaluation of chest pain or arrhythmia of unclear etiology. "Missed" clinical diagnosis frequently involved patients with mitral valve prolapse, congestive cardiomyopathy, pericardial disease or asymmetrical septal hypertrophy of the heart. This study quantifies the amount of independent information contributed by echocardiography to cardiac diagnosis and demonstrates that this technic provides data of important clinical relevance in a surprisingly large number of cardiac patients.

Polysplenia syndrome. A study of five new cases.

Five children with polysplenia syndrome are described. Cardiac catheterization or postmortem examination revealed the following cardiac anomalies: interruption of the inferior vena cava with azygos (or hemiazygos) continuation to the left superior vena cava and a single atrium or a large atrial septal defect in all five children; a ventricular septal defect in three; and a primitive ventricle in one case. Other anomalies found were: central liver in all five; a right-sided stomach in three; and multiple small spleens and bilateral left, bilobed lungs--found on autopsy--in two of the children. In four of the five patients, whose ECG was available, a negative P wave was present in leads II, III and AVF. This leftward and superiorly directed P wave axis should suggest a diagnosis of polysplenia syndrome in an infant with congenital heart disease. The cardiac anomalies are surgically correctable; therefore, early recognition of this syndrome is of practical importance.

Cardiac involvement and superior vena caval obstruction in Behçet's disease.

A patient with Behçet's disease developed the rare complications of pericarditis and, two months later, superior vena caval obstruction. The latter complication was investigated by angiography to exclude other causes. As a result of this investigation the caval obstruction was managed conservatively, the symptoms and signs improving spontaneously.