Vincent L. Sorrell

Increased mortality among patients taking digoxin—analysis from the AFFIRM study

AIMS Digoxin is frequently used for rate control of atrial fibrillation (AF). It has, however, been associated with increased mortality. It remains unclear whether digoxin itself is responsible for the increased mortality (toxic drug effect) or whether it is prescribed to sicker patients with inherently higher mortality due to comorbidities. The goal of our study was to determine the relationship between digoxin and mortality in patients with AF. METHODS AND RESULTS The association between digoxin and mortality was assessed in patients enrolled in the AF Follow-Up Investigation of Rhythm Management (AFFIRM) trial using multivariate Cox proportional hazards models. Analyses were conducted in all patients and in subsets according to the presence or absence of heart failure (HF), as defined by a history of HF and/or an ejection fraction <40%. Digoxin was associated with an increase in all-cause mortality [estimated hazard ratio (EHR) 1.41, 95% confidence interval (CI) 1.19-1.67, P < 0.001], cardiovascular mortality (EHR 1.35, 95% CI 1.06-1.71, P = 0.016), and arrhythmic mortality (EHR 1.61, 95% CI 1.12-2.30, P = 0.009). The all-cause mortality was increased with digoxin in patients without or with HF (EHR 1.37, 95% CI 1.05-1.79, P = 0.019 and EHR 1.41, 95% CI 1.09-1.84, P = 0.010, respectively). There was no significant digoxin-gender interaction for all-cause (P = 0.70) or cardiovascular (P = 0.95) mortality. CONCLUSION Digoxin was associated with a significant increase in all-cause mortality in patients with AF after correcting for clinical characteristics and comorbidities, regardless of gender or of the presence or absence of HF. These findings call into question the widespread use of digoxin in patients with AF.

Robotic mitral valve repair: experience with the da Vinci system.

BACKGROUND As part of a Food and Drug Administration trial, mitral repairs were performed in 38 patients using the robotic da Vinci surgical system (Intuitive Surgical, Inc, Mountain View, CA). Prospectively, we evaluated safety and efficacy in performing both simple and complex mitral repairs. METHODS Eligible patients had nonischemic moderate to severe mitral insufficiency. Operative techniques included peripheral cardiopulmonary perfusion, a 4- to 5-cm mini-thoracotomy, transthoracic aortic occlusion, and antegrade blood cardioplegia. Transesophageal echocardiograms were done intraoperatively with three-dimensional reconstructions. Successful repairs were defined as mild or less residual regurgitation. RESULTS Enhanced three-dimensional visualization of mitral leaflets and the subvalvar apparatus allowed safe, dexterous intracardiac tissue manipulation. All patients had successful valve repairs including quadrangular resections, sliding plasties, and edge-to-edge approximations, as well as both chordal transfers and replacements. There were no operative deaths, strokes, or device-related complications. One patient required valve replacement for hemolysis and 1 was reexplored for bleeding. There were no incisional conversions. Both robotic repair and total operating times decreased significantly from 1.9 +/- 0.1 and 5.1 +/- 0.1 hours (mean +/- standard error of the mean) for the first 19 patients to 1.5 +/- 0.1 (p = 0.002) and 4.4 +/- 0.1 hours (p = 0.04) for the last 19 operations, respectively. Total hospital length of stay for patients was 3.8 +/- 0.6 days. Of all patients, 31 (82%) had a 4-day or less length of stay. Seven patients (18%) had stays between 5 and 9 days (6.4 +/- 1.0). CONCLUSIONS This study shows that the da Vinci surgical system (Intuitive Surgical, Inc) has few limitations in performing complex valve repairs. Articulated wrist-like instruments and three-dimensional visualization enabled precise tissue telemanipulation. Future robotic design advances and adjunctive suture technologies may promote continuing evolution of robotic cardiac operations.

Protocol for optimal detection and exclusion of a patent foramen ovale using transthoracic echocardiography with agitated saline microbubbles.

Agitated saline bubble studies in conjunction with echocardiography, in particular transesophageal echocardiography, are currently the principal means in the diagnosis of patent foramen ovale (PFO). We describe techniques and guidelines for the detection and exclusion of a PFO. The potential for misinterpretation of these bubble studies exists and therefore, several false positive and false negative scenarios are illustrated and discussed.

Peripartum cardiomyopathy: Causes, diagnosis, and treatment

Peripartum cardiomyopathy is a life-threatening condition of unknown cause that occurs in previously healthy women during the peripartum period. It is characterized by left ventricular dysfunction and symptoms of heart failure that can arise in the last trimester of pregnancy or up to 5 months after delivery. We review its possible causes and how to recognize and manage it.

Degenerative aortic stenosis

#### Summary points Aortic stenosis is the most common valvular lesion in Europe and North America. It primarily presents as calcific aortic stenosis in 2-7% of the population aged >65 years.1 About 80% of adult patients with symptomatic aortic stenosis are male. As 1-2% of the population is born with a congenital bicuspid aortic valve and populations are ageing, aortic stenosis is becoming more common. By 2020, about 3.5 million people in England are expected to have aortic sclerosis and 150 000 will have severe aortic stenosis.2 Here we provide an overview to help diagnosis and a summary of the management of AS and its sequelae. Many of the points made in this review are based on randomised controlled trials. However, observational studies and the guideline recommendations of the American Heart Association and the American College of Cardiology and of the European Society of Cardiology are also included to provide comprehensive overviews that are beyond the scope of this article. The most common cause of aortic stenosis in adults is calcification of a normal trileaflet (fig 1⇓). Calcific aortic stenosis is thought to be a degenerative process that shares many features with coronary artery disease, such as lipid accumulation, …

Magnetic Resonance Imaging During Untreated Ventricular Fibrillation Reveals Prompt Right Ventricular Overdistention Without Left Ventricular Volume Loss

Background—Most out-of-hospital ventricular fibrillation (VF) is prolonged (>5 minutes), and defibrillation from prolonged VF typically results in asystole or pulseless electrical activity. Recent visual epicardial observations in an open-chest, open-pericardium model of swine VF indicate that blood flows from the high-pressure arterial system to the lower-pressure venous system during untreated VF, thereby overdistending the right ventricle and apparently decreasing left ventricular size. Therefore, inadequate left ventricular stroke volume after defibrillation from prolonged VF has been postulated as a major contributor to the development of pulseless rhythms. Methods and Results—Ventricular dimensions were determined by MRI for 30 minutes of untreated VF in a closed-chest, closed-pericardium model in 6 swine. Within 1 minute of untreated VF, mean right ventricular volume increased by 29% but did not increase thereafter. During the first 5 minutes of untreated VF, mean left ventricular volume increased by 34%. Between 20 and 30 minutes of VF, stone heart occurred as manifested by dramatic thickening of the myocardium and concomitant substantial decreases in left ventricular volume. Conclusions—In this closed-chest swine model of VF, substantial right ventricular volume changes occurred early and did not result in smaller left ventricular volumes. The changes in ventricular volumes before the late development of stone heart do not explain why defibrillation from brief duration VF (<5 minutes) typically results in a pulsatile rhythm with return of spontaneous circulation, whereas defibrillation from prolonged VF (5 to 15 minutes) does not.

Pitfalls in the Diagnosis of Arrhythmogenic Right Ventricular Cardiomyopathy/Dysplasia

The diagnosis of arrhythmogenic right ventricular cardiomyopathy/dysplasia is determined according to Task Force Criteria published in 1994 that included imaging abnormalities of the right ventricle and diagnostic pathologic evaluation findings of the right ventricular myocardium by endomyocardial biopsy. These have recently been modified to include evaluation using cardiac magnetic resonance imaging. In addition, quantitative criteria for the percentage of fibrosis and the decrease in myocytes have been included in the new criteria. The pitfalls of determining the presence of arrhythmogenic right ventricular cardiomyopathy/dysplasia at autopsy and the difficulty in assessing the presence of this disease in family members are well illustrated in the present report. In conclusion, we have illustrated the need to subscribe to the modified criteria to avoid misdiagnosis.

Accelerometer‐Derived Time Intervals during Various Pacing Modes in Patients with Biventricular Pacemakers: Comparison with Normals

Introduction: Changes due to biventricular pacing have been documented by shortening of QRS duration and echocardiography. Compared to normal ventricular activation, the presence of left bundle branch block (LBBB) results in a significant change in cardiac cycle time intervals. Some of these have been used to quantify the underlying cardiac dyssynchrony, assess the effects of biventricular pacing, and guide programming of ventricular pacing devices. This study evaluates a simple noninvasive method using accelerometers attached to the skin to measure cardiac time intervals in biventricularly paced patients.

The "hurricane sign": evidence of patient motion artifact on cardiac single-photon emission computed tomographic imaging.

Single-photon emission computed tomography (SPECT) is frequently used with myocardial perfusion imaging in the assessment of patients with known or suspected coronary artery disease. The susceptibility of SPECT imaging to artifact, especially that caused by patient motion, has long been recognized. We report a characteristic artifact of patient motion, which we have termed the “hurricane sign” because of its similarity to the National Weather Service Symbol for a hurricane. This artifact is caused by varying contributions of different portions of the heart during image acquisition and their misalignment produced by patient motion.

Poor Correlation of Estimated Pulmonary Artery Systolic Pressure Between Echocardiography and Right Heart Catheterization in Patients Awaiting Cardiac Transplantation: Results From the Clinical Arena

BACKGROUND Pulmonary arterial pressure measurement is an integral part of the pre-heart transplant evaluation. In the clinical arena, the correlation and agreement between pulmonary artery systolic pressure (PASP) measured by Doppler echocardiography versus catheterization in pre-heart transplant patients has not been studied. METHODS Data on all patients evaluated for heart transplantation at our program between 2003 and 2005 (n = 176) were retrospectively reviewed. Patients with both transthoracic echocardiography (with interpretable images) and right heart catheterization performed were included (n = 108; mean time difference, 2.2 days; median, 2 days). The tricuspid valve regurgitant jet was identified by color flow Doppler and jet maximum velocity was measured by continuous wave Doppler. The PASP was estimated by using the modified Bernoulli equation and adding right atrial pressure. We correlated echocardiographically estimated PASP with that measured by right heart catheterization. RESULTS Mean estimated PASP by echocardiography was 46.6 +/- 13.7 mmHg versus 44.8 +/- 17.9 mmHg by right heart catheterization (P = NS). However, the correlation between echocardiographic and measured PASP was poor (r = 0.49, P < .001). The correlation was poor in both ischemic and nonischemic cardiomyopathy. CONCLUSION Among patients referred for heart transplant evaluation, there is poor agreement and correlation between echocardiographically estimated PASP and values obtained by right heart catheterization. Furthermore, echocardiographically obtained estimates of PASP should not be exclusively relied upon to exclude heart transplant recipient candidates.