Anis I. Obeid

Comparison of transthoracic and transesophageal echocardiography in diagnosis of left atrial myxoma

Abstract Since its introduction, M-mode echocardiography became quickly established as the method of choice in the diagnosis of left atrial (LA) myxoma. 1 Further definition of tumor size, mobility, site of attachment and other features became possible with the evolution of 2-dimensional echocardiography, henceforth referred to as transthoracic echocardiography (TTE). 2 The introduction of transesophageal echocardiography (TEE) provided the echocardiographer with a new window through which an unimpeded view of both atria and atrial septum became possible with high degrees of resolution and accuracy. 3,4 The following is a report of 3 patients with surgically proven LA myxoma, who were investigated preoperatively with TTE and TEE.

Effects of sublingual nitroglycerin on resting pulmonary gas exchange and hemodynamics in man.

Simultaneous hemodynamic, ventilation and blood gas measurements were performed in 19 males during cardiac catheterization for evaluation of chest pain syndrome before and 3 to 5 min after 0.4 mg sublingual nitroglycerin. Pulmonary arterial pressures and total pulmonary vascular resistance fell (P < 0.001 for both), and mean systemic arterial pressure decreased (P < 0.05). However, peripheral vascular resistance, cardiac output, and mixed venous PG2 did not change. Total and tidal ventilation, PCO2, pH, and base excess remained unchanged. However, the arterial PO, decreased from a mean of 80 ± 3 (SEM) to 72 ± 2 mm Hg (P < 0.001) and mean venous admixture increased from 8.8 ± 1% to 12.6 ± 1.5% (P < 0.001). The alveolararterial P02 difference increased (P < 0.001) and the dead space tidal volume ratio rose (P < 0.05). We conclude that the decrease in arterial P02 following sublingual nitroglycerin is caused by redistribution of pulmonary blood flow with imbalance in ventilation-perfusion relationships or shunting.

Variant Anginal Syndrome, Coronary Artery Spasm, and Ventricular Fibrillation in Absence of Chest Pain

Excerpt To the editor: Ventricular tachyarrhythmias and strong propensity to ventricular fibrillation (1) have been observed frequently in Prinzmetals angina. Two patients with arrhythmias in the ...

Approach in the Management or Atrial Myxoma with Long-term Follow-up

Between 1972 and 1982, 9 patients underwent successful excision of atrial myxomas at the Upstate Medical Center. Eight patients had a left atrial myxoma and 1 a biatrial myxoma. There were 5 female and 4 male patients ranging from 16 to 63 years of age. Preoperative findings consisted of cerebral or peripheral emboli, congestive heart failure, and nonspecific symptoms. Diagnosis was confirmed by echocardiography and angiography in all but 1 patient. A biatrial operative approach was utilized in all patients except 1. Complete excision of the tumor with a cuff of normal tissue was performed. All heart chambers were carefully explored for presence of multicentric myxomas or tumor debris. There were no operative deaths or intraoperative embolizations. Follow-up has been 1 1/2 to 11 years. There has been 1 late noncardiac death. All patients underwent echocardiography postoperatively with no recurrence. The risk of intraoperative embolization and late recurrence is minimal with the biatriotomy technique. Two-dimensional echocardiography is extremely accurate in early diagnosis of myxomas and in the late follow-up of patients.

Refractory paroxysmal supraventricular tachycardia: Treatment with patient controlled permanent radio frequency atrial pacemaker☆

Abstract A patient with incapacitating recurrent supraventricular tachycardia, refractory to medical management, was evaluated for possible surgical intervention. Several types of competitive artificial pacemakers were considered, as was surgical section of the His bundle plus conventional pacing. The patient was treated with a competitive, radio-frequency-coupled atrial pacemaker, which she herself operates to break her supraventricular tachycardias. The device has operated successfully on numerous occasions for over 15 months. Several other aspects of this patients arrhythmias were discussed.

Evaluation of pulmonary vein stenosis by transesophageal echocardiography

Pulmonary vein stenosis was diagnosed by transesophageal echocardiography in five patients who underwent the study for different clinical indications. Stenosis was encountered in the right upper pulmonary vein in two patients, the right lower pulmonary vein in two patients, and at the confluence of the left pulmonary veins in one patient. In only one patient was the diagnosis suspected on transthoracic echocardiography. Contralateral normal veins from the same patient served as the control. Vessel diameter and peak flow velocity were measured and compared. The diameter of the stenosed veins ranged from 0.3 to 0.8 cm (mean 0.4 +/- 0.09 cm [SEM]), whereas for normal veins the diameter was 0.9 to 1.2 cm (mean 1.0 +/- 0.05 cm [SEM]; p < 0.001). Peak flow velocity in the stenosed veins ranged from 1.1 to 1.6 m/sec (mean 1.4 +/- 0.1 m/sec [SEM]), whereas in normal veins peak flow velocity ranged from 0.4 to 0.7 m/sec (mean 0.6 +/- 0.04 m/sec [SEM]; p < 0.001). There was a strong negative correlation between vessel diameter and peak flow velocity (R = 0.89; p < 0.001). Peak flow velocity of 0.8 m/sec appears to provide the best separation between normal and stenosed pulmonary veins. We conclude that pulmonary vein stenosis is associated with increased flow velocity and turbulence and deformity of the flow signal. Transesophageal echocardiography is a powerful tool in the study of pulmonary vein stenosis.

Regional metabolic changes in the myocardium following coronary artery ligation in dogs

Abstract Metabolic and hemodynamic changes were studied in dogs before and at 5 minute intervals following ligation of the anterior descending coronary artery. By placing catheters in the arterial (A), main coronary sinus (CS), and great cardiac vein (CV) positions, it was possible to collect simultaneous samples from the three sites and analyze the effluent for pH, Po 2 , potassium, glucose, pyruvate, and lactate. Following coronary ligation, there was a significant decrease in pH and glucose and an increase in lactate and potassium in the CV samples. The Po 2 value did not change significantly. The CS drainage exhibited minor changes and only when the changes in the CV samples were marked. The hemodynamic changes included a slight fall in blood pressure, an increase in isovolumetric contraction period, and an increase in left ventricular end-diastolic pressure following coronary ligation. The results and the technique are discussed with emphasis on metabolic alterations in regional venous drainage following coronary artery ligation.

Primary osteosarcoma of left atrium: complete surgical excision

A patient with primary osteogenic sarcoma of the left atrium with clinical features of severe congestive heart failure is described. The operative procedure required excision of the posterior atrial wall in continuity with the left pulmonary veins. The resultant defect in the atrium was reconstructed with the left atrial appendage. The left pulmonary artery was ligated, and the lung was removed at a subsequent procedure. The patient survived operation but subsequently was found to have distant metastasis. He died seven months after the operation.

Gas Endarterectomy of Right Coronary Artery The Importance of Proximal Bypass Graft

Results of gas endarterectomy of the right coronary artery were evaluated in 29 consecutive patients. There were one surgical and two early postsurgical deaths. All three had postmortem examination, and in two there was occlusion of the gas endarterectomy. Five patients did not have repeat catheterization. Twenty-one patients were completely re-evaluated and had repeat cardiac catheterization one to sixteen months after surgery (mean eight months). Ten patients (Group A) had gas endarterectomy without a saphenous vein graft to the right coronary artery. Only one patient had significant vessel patency. Eleven patients (Group B) had the combined procedure of a saphenous vein graft anastomosed to the segment of artery that had the endarterectomy. There was excellent graft patency in seven patients (64%) and good distal flow into the segment that had endarterectomy in six of the seven patients. In conclusion, gas endarterectomy is not of value unless it can be combined with a saphenous vein graft to provide good flow to the distal vessel that had endarterectomy. Results with the combined procedure suggest that even with a severely diseased artery, gas endarterectomy can often provide continuing distal runoff for the graft.

Fluid Therapy in Severe Systemic Reaction to Radiopaque Dye

Two patients developed severe vascular collapse after left ventriculography with organic iodides. Hemodynamic monitoring showed marked reduction in systemic pressures. In one patient there was no response to the standard therapeutic measures in anaphylactic reactions, and prompt response to fluid administration was obtained. In the second patient response was prompt to fluids, adrenalin, and hydrocortisone.