The angiographic prevalence, clinical predictors, and sensitivity and specificity of a bilateral arm blood pressure differential for predicting proximal left subclavian artery stenosis were established in 492 patients undergoing cardiac catheterization. Seventeen subjects (3.5%) in the overall population and nine subjects (5.3%) with potential surgical coronary disease had proximal left subclavian stenosis. Precatheterization evidence of peripheral vascular disease (PVD) was the only predictor of subclavian stenosis in the overall population (P < 0.001; OR = 7.9; 95% CI = 2.6-24.3) and in patients with potential surgical coronary disease (P = 0.04; OR = 5.4; 95% CI = 1.1-27.2). Both a bilateral blood pressure differential of > 10 mm Hg and of > or =20 mm Hg had a good specificity but a poor sensitivity for predicting left subclavian stenosis. Thus, left subclavian angiography should be performed in patients with surgical coronary disease with either an arm blood pressure differential of > 10 mm Hg or with other precatheterization evidence of PVD. Cathet Cardiovasc Intervent 2001;54:8-11.

The purpose of this study was to examine the effects of ablation of the superficial endocardium and Purkinje network on left ventricular fibrillation threshold. Lugol's solution was applied through small ventriculotomies to the left and right ventricular endocardium of 10 dogs on cardiopulmonary bypass. Two control groups of five animals each underwent either endocardial application of saline or epicardial application of Lugol's solution. perimentally to be an important substrate in ventricular tachycardia, its role in ventricular fibrillation is less clear.'2-' Nevertheless, transmural recordings during ventricular fibrillation have documented endocardial to epicardial spread of activation with variable block, implying an endocardial origin of many of the activation fronts that maintain the arrhythmia.'9The purpose of this study was to examine the effect of ablation of the superficial endocardium and Purkinje fiber network on the ability to initiate ventricular fibrillation. Lugol's solution, a concentrated iodine solution, has an affinity for glycogen. It has been demonstrated to stain and ablate both Purkinje fibers and endocardial tissue.2>22 In this study, the electrophysiologic effects of the endocardial application of Lugol's solution on ventricular fibrillation threshold were examined. In addition, the rheologic and histologic changes induced by this procedure were also investigated. MethodsTwenty adult mongrel dogs weighing 25 to 35 kg were anesthetized with intravenous sodium pentobarbitol (30 mg/kg) and maintained on a constant-drip infusion of 2 mg/min throughout the study.

Phrenic nerve injury following cardiac surgery is variable in its incidence depending on the diligence with which it is sought. Definitive studies have shown this complication to be related to cold‐induced injury during myocardial protection strategies and possibly to mechanical injury during internal mammary artery harvesting. The consequences are also variable and depend to a large extent on the underlying condition of the patient, particularly with regard to pulmonary function. The response of the patient may range from an asymptomatic radiographic abnormality to severe pulmonary dysfunction requiring prolonged mechanical ventilation and other associated morbidities and even mortality. Two cases are presented to demonstrate the variability in clinical responses to diaphragmatic dysfunction secondary to phrenic nerve injury from cardiac surgery. In addition, treatment strategies are reviewed including early tracheostomy and diaphragmatic plication, which appear to be the most effective options for patients who are compromised by phrenic injuries.

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