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Biomedical subjects

S Amikam

Publications and source records attributed to S Amikam.

At least 37 records · Page 2Linked to original sources

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.

Aged↗

Myotonia dystrophica with heart involvement: an electron microscopic study of skeletal, cardiac, and smooth muscle.

The electron microscopic features of the striated skeletal muscle, the striated cardiac muscle, and the smooth muscle from a woman who had been suffering for many years from myotonia dystrophica with cardiac involvement are described. The skeletal muscle was studied at two different stages of the disease. In the first material the main changes consisted of centrally situated nuclei, disorganisation of the sarcomeres, and focal disruption of the Z-line. The satellite cells were well represented. Three years later atrophy and degenerative, necrotic changes of the skeletal muscle were evident. The satellite cells were absent. Few changes were seen in the striated cardiac muscle. These consisted of slight interstitial fibrosis and large accumulations of mitochondria with intramitochondrial dense granules. The smooth muscle cells of the oesophagus showed disorientated filaments and mild degenerative changes. It is concluded that the skeletal muscle was more severely affected than the other types of muscle.

Aorta↗

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.

Abnormalities, Multiple↗

Myopotential inhibition of a bipolar pacemaker caused by electrode insulation defect.

A patient is described in whom myopotentials orginating from the anterior abdominal wall muscle suppressed the implanted demand pacemaker despite its bipolar mode of action. This phenomenon was shown by simultaneous recording of the electrocardiogram the electromyogram. At operation, a defect in the insulation of a previously repaired epicardial electrode was found lying in close proximity to these muscles. After repair of the insulation defect, normal pacemaker function was restored. It is suggested that the myopotentials leaked into the pacing system through the insulation defect, thereby suppressing the demand unit, which maintained its bipolar mode of pacing throughout.

Abdominal Muscles↗

Primary ST changes. Diagnostic aid in paced patients with acute myocardial infarction.

In 34 out of 36 patients with apical right ventricular endocardial pacing, primary ischaemic ST alterations were observed during the early stage of acute myocardial infarction. These ST changes, indicating acute injury, were detected in the paced beats in inferior and in anterior infarct. The primary ST changes were consistent only during the early stages of acute myocardial infarction and were not detected when the electrode tip was not in the apex of the right ventricle. It is suggested that the primary ST changes should be used to diagnose acute myocardial infarction in paced patients.

Acute Disease↗

Prolapsing right atrial myxoma: clinical and heamodynamic considerations.

A 22-year-old woman with a right atrial myxoma prolapsing to the right ventricle is described. The haemodynamic findings were similar to those of cases of prolapsing myxoma of the left atrium; a notching on the ascending limb of the right ventricular pressure curve, and an initial negative, irregular deflection on the pulmonary artery pressure curve with a pronounced rise in the mean right atrial pressure (18 mmHg) were found. On deep inspiration there was a significant deepening of the y descent from 12 mmHg to 2 mmHg, indicating a changing, dynamic obstruction of the right ventricle inflow tract. These haemodynamic features can be helpful in the diagnosis of prolapsing right atrial myxoma.

Adult↗

Permanent right ventricular pacing through an anomalous left superior vena cava.

A persistent left superior vena cava can complicate the implantation of a transvenous pacemaker. In a patient who required a permanent pacemaker, this venous anomaly was discovered during the insertion of the electrode but it did not prevent long-term right ventricular pacing. This was achieved after the electrode had been manipulated through the coronary sinus and right atrium. A plan of management is proposed for dealing with this unexpected problem.

Atrial Fibrillation↗

Long-term survival of elderly patients after pacemaker implatation.

The follow-up of 80 patients above the age of 70 years with implanted pacemakers is described. These patients were the most advanced in age from a total group of 150 with implanted pacemakers. Their ages ranged from 70 to 87 years, with an average of 75.4 years; 50 were male and 30 were female. An epicardial electrode was implanted in 13 patients and an endocardial electrode in 67. The pacemaker was implanted in 76 patients for symptomatic atrioventricular block and in four patients for sick-sinus syndrome. Two patients (2.5 per cent) died during the postoperative period and 19 patients within a period of 3 months to 6 years after the implantation. The survival rates were: 1 year, 90.0 per cent; 2 years, 82.1 per cent; 3 years, 74.1 per cent; 4 years, 67.2 per cent; 5 years, 58.3 percent. These survival rates were surprisingly similar, for the first 3 years of follow-up, to those of our and others' previous studies, which included all age groups. The survival rates in the most advanced age groups decreased in comparison only in fourth and fifth years after the implantation. There was no evidence of new episodes of myocardial infarction among this group of patients during the follow-up period. We conclude that even in patients of the most advanced age groups the implantation of an endocardial pacemaker significantly prolongs life, improves its quality, and this at a low operative risk.

Aged↗

Changing haemodynamics in patient with papillary muscle dysfunction.

A patient with papillary muscle disease caused by myocardial infarction was studied before and after injection of phenylephrine. The pulmonary wedge pressure was normal at rest. However, pressures and murmur changes, occurring spontaneously and after injection of phenylephrine, suggested that intermittent severe mitral regurgitation contributed significantly to the recurrent episodes of acute left heart failure presented by this patient.

Blood Pressure↗

Electron microscopical study of myocardial biopsy material in congenital heart block.

Myocardial tissue from the left ventricle of two children with congenital atrioventricular block and recurrent Admas-Stokes attacks was obtained during the procedure of epicardial pacemaker implantation and studied with the electron microscope. One patient had a familial cardiomyopathy, the other had no clinical abnormality apart from the conduction defect. Proliferation of mitochondria was common in both cases. Focal interstitial fibrosis and pronounced proliferation of transverse tubules were found in the myocardial cells of the patient with familial cardiomyopathy. Deep invaginations of the sarcolemmma with formation of intracytoplasmic channels were present in the second case. The possibility that the numerous transverse tubules could serve as additional pathways for impulse conduction is discussed.

Adams-Stokes Syndrome↗