Chest Pain Evaluation: Diagnostic Testing.

Chest pain/discomfort (CP) is a common symptom and can be a diagnostic dilemma for many clinicians. The misdiagnosis of an acute or progressive chronic cardiac etiology may carry a significant risk of morbidity and mortality. This review summarizes the different options and modalities for establishing the diagnosis and severity of coronary artery disease. An effective test selection algorithm should be individually tailored to each patient to maximize diagnostic accuracy in a timely fashion, determine short- and long-term prognosis, and permit implementation of evidence-based treatments in a cost-effective manner. Through collaboration, a decision algorithm was developed (www.chowmd.ca/cadtesting) that could be adopted widely into clinical practice.

La douleur ou la gêne thoracique sont des symptômes fréquents qui peuvent poser un dilemme diagnostique pour de nombreux médecins. Les erreurs de diagnostic d'une cause aiguë ou chronique progressive d'origine cardiaque peuvent d'ailleurs entraîner un risque considérable de morbidité et de mortalité. La présente synthèse porte sur les différentes options et modalités d'établissement du diagnostic et de la gravité d'une coronaropathie. Un algorithme efficace pour le choix des tests doit être adapté à chaque patient afin de maximiser l'exactitude diagnostique dans les plus brefs délais, de déterminer le pronostic à court et à long terme, et de permettre une mise en œuvre de traitements fondés sur des données probantes tout en tenant compte des coûts. Un algorithme décisionnel a donc été conjointement mis au point (www.chowmd.ca/cadtesting) et pourrait être largement adopté dans la pratique clinique.

Electrophysiology Study and Catheter Ablation With Superior Vena Cava Stump.

We report the complete absence of a superior vena cava in a patient without prior history of cardiac surgery or device implantation. This is a very rare congenital cardiac abnormality, which if unrecognized, may lead to complications in patients undergoing electrophysiological studies.

Activity with ambulation attenuates diuretic responsiveness in chronic heart failure.

INTRODUCTION: We hypothesized that discharged heart failure (HF) patients could develop clinical congestion despite adhering to prescribed diuretics, because ambulation attenuates diuretic and natriuretic responsiveness. METHODS: We studied 9 patients aged 57 ± 13 (mean ± SD) years with New York Heart Association functional class II-III symptoms and ejection fraction <40% (28 ± 7%) and receiving furosemide (≥80 mg/d [113 ± 53 mg/d]) plus renin-angiotensin system antagonists and beta-blockade. Inulin and p-amminohippuric acid were infused to estimate glomerular filtration rate (GFR) and renal plasma flow (RPF). Furosemide was administered intravenously at 75% of the usual oral morning dose. Participants were randomized to supine (90 minutes recumbancy) or upright (90 minutes sitting and treadmill walking) posture and assumed the other position on their second day. Primary outcome variables were urine volume and sodium excretion 90 minutes after furosemide. RESULTS: On the upright, compared with the supine, day, urine volume (792 ± 484 vs 1,290 ± 503 mL; P = .02) and sodium (79 ± 55 vs 141 ± 61 mmol; P < .01) were attenuated, whereas plasma norepinephrine (4.4 ± 2.7 vs 2.3 ± 1.8 mmol/L; P = .01) and renin (327 ± 250% of supine; P < .01) were augmented. Urinary K+, mean pressure, GFR, and RPF were similar. CONCLUSIONS: Activation of the sympathetic nervous system and renin-angiotensin axis by upright ambulation may attenuate diuresis and natriuresis by increasing proximal tubular reabsorption of sodium and water.

Prognostic value of 64-slice cardiac computed tomography severity of coronary artery disease, coronary atherosclerosis, and left ventricular ejection fraction.

OBJECTIVES: We sought to determine the prognostic and incremental value of coronary artery disease (CAD) severity, coronary atherosclerosis, and left ventricular ejection fraction (LVEF) measured with cardiac computed tomography angiography (CTA). BACKGROUND: CTA is an emerging tool used for the detection of obstructive CAD. However, there are limited data supporting the prognostic value of 64-slice CTA and its ability to predict all-cause mortality and major adverse cardiac events such as cardiac death and nonfatal myocardial infarction. METHODS: Consecutive patients (without history of revascularization, heart transplantation, and congenital heart disease) were prospectively enrolled. Each CTA was evaluated for CAD severity, total plaque score, and LVEF. Patients were followed, and all events were confirmed with death certificates or hospital or physician records and reviewed by a clinical events committee. RESULTS: Between February 2006 and February 2008, 2,076 consecutive patients were prospectively enrolled and followed for a mean of 16 +/- 8 months. At follow-up, a total of 31 (1.5%) patients had cardiac death or nonfatal myocardial infarction and 47 (2.3%) had all-cause mortality or nonfatal myocardial infarction. Multivariate analysis showed that CAD severity (hazard ratio [HR]: 3.02; 95% confidence interval [CI]: 1.89 to 4.83) was a predictor of major adverse cardiac events and that LVEF (HR: 1.47; 95% CI: 1.17 to 1.86) had incremental value over CAD severity. Total plaque score had incremental value over CAD severity and LVEF for all-cause mortality and nonfatal myocardial infarction (HR: 1.17; 95% CI: 1.06 to 1.29). CONCLUSIONS: Using CTA, CAD severity, LVEF, and total plaque score seems to have prognostic and incremental value over routine clinical predictors. Cardiac CTA seems to be a promising noninvasive modality with prognostic value.

Mycophenolate mofetil dose reduction for gastrointestinal intolerance is associated with increased rates of rejection in heart transplant patients.

BACKGROUND: Gastrointestinal (GI) intolerance to mycophenolate mofetil (MMF) is a frequent problem. We conducted a retrospective analysis of all the heart transplant patients followed up at the Toronto General Hospital from the years 1999 to 2006 to determine the impact of dose reductions for GI intolerance on rejection rates. METHODS: The charts of all patients followed up in the heart transplant clinic at the Toronto General Hospital from the years 1999 to 2006 were reviewed. Sustained significant rejection was defined as an International Society of Heart and Lung Transplantation grade 2 or higher on 2 successive biopsies. The Student's t-test was used to compare rates of rejection between populations. RESULTS: Mycophenolate mofetil was part of the anti-rejection regimen in 182 of 189 patients (98%), and the medication dose in 71% of these patients had to be reduced at some point because of intolerance or toxicity. The prevalence of sustained significant rejection was significantly higher in the group of patients with GI intolerance to MMF compared with patients maintained on target doses (66% vs 35%, p = 0.002) or patients with non-GI related toxicities necessitating dose reduction (67% vs 35%, p = 0.003). CONCLUSION: Gastrointestinal intolerance is a common reason for MMF dose reduction in heart transplant patients and was associated with a significantly increased rate of sustained rejection, suggesting that these individuals need to have particularly close follow-up.

Inferior infarction following alcohol septal ablation: a consequence of "collateral damage"?

Alcohol septal ablation is fast becoming the most common method to reduce left ventricular outflow tract gradient in patients with symptomatic hypertrophic obstructive cardiomyopathy. Myocardial contrast echocardiography (MCE) is routinely used as an adjunct to avoid the spread of alcohol to non-target areas of myocardium. We report two cases where despite the careful use of MCE, remote inferior wall myocardial infarctions occurred. The likely mechanism and possible preventive measures are discussed.