Ezra Dweck

Clinical improvement with repeated courses of intravenous B-type natriuretic peptide in refractory heart failure.

Congestive heart failure (CHF) is characterized by increased salt and water retention by the kidneys in response to decreased renal blood flow. Increased sympathetic nerve activity is also seen in response to a low cardiac output. Although these compensatory mechanisms are initially important for augmenting cardiac output in a failing ventricle, they ultimately lead to volume overload. B-type natriuretic peptide (BNP), a hormone secreted by the heart in response to increased left ventricular wall tension, is now available as a pharmacolgic agent. BNP interferes with renal mechanisms for salt and water retention and may also inhibit sympathetic nerve activity. We report a patient with New York Heart Association (NYHA) class IV CHF who had dramatic, cyclic clinical improvement due to three repeated courses of intravenous BNP. This patient’s marked improvement in clinical and hemodynamic parameters with BNP was superior to that seen in other patients we have treated with intravenous inotropes.

Postoperative Tachycardia: Clinically Meaningful or Benign Consequence of Orthopedic Surgery?

Objective: To determine the clinical significance of tachycardia in the postoperative period. Patients and Methods: Individuals 18 years or older undergoing hip and knee arthroplasty were included in the study. Two data sets were collected from different time periods: development data set from January 1, 2011, through December 31, 2011, and validation data set from December 1, 2012, through September 1, 2014. We used the development data set to identify the optimal definition of tachycardia with the strongest association with the vascular composite outcome (pulmonary embolism and myocardial necrosis and infarction). The predictive value of this definition was assessed in the validation data set for each outcome of interest, pulmonary embolism, myocardial necrosis and infarction, and infection using multiple logistic regression to control for known risk factors. Results: In 1755 patients in the development data set, a maximum heart rate (HR) greater than 110 beats/min was found to be the best cutoff as a correlate of the composite vascular outcome. Of the 4621 patients who underwent arthroplasty in the validation data set, 40 (0.9%) had pulmonary embolism. The maximum HR greater than 110 beats/min had an odds ratio (OR) of 9.39 (95% CI, 4.67–18.87; sensitivity, 72.5%; specificity, 78.0%; positive predictive value, 2.8%; negative predictive value, 99.7%) for pulmonary embolism. Ninety‐seven patients (2.1%) had myocardial necrosis (elevated troponin). The maximum HR greater than 110 beats/min had an OR of 4.71 (95% CI, 3.06–7.24; sensitivity, 47.4%; specificity, 78.1%; positive predictive value, 4.4%; negative predictive value, 98.6%) for this outcome. Thirteen (.3%) patients had myocardial infarction according to our predetermined definition, and the maximum HR greater than 110 beats/min had an OR of 1.72 (95% CI, 0.47–6.27). Conclusion: Postoperative tachycardia within the first 4 days of surgery should not be dismissed as a postoperative variation in HR, but may precede clinically significant adverse outcomes.