Safety of endoscopic procedures after acute myocardial infarction: A systematic review

Background: The management of patients who develop gastrointestinal (GI) bleeding after acute myocardial infarction (MI) is difficult due to concerns about possible cardiovascular complications. Gastroenterologists are often reluctant to perform endoscopic procedures despite urgent indications. We performed a systematic review of the literature to determine the safety of endoscopic procedures after MI. Methods: We searched MEDLINE, EMBASE and the Cochrane Central Register of Controlled trials for controlled clinical trials or case series examining the diagnostic efficacy and complications of esophagogastroduodenoscopy (EGD), colonoscopy and flexible sigmoidoscopy after MI. Title and abstract screening was followed by full-text review with subsequent data extraction of included studies. Results: A total of seven studies met inclusion criteria. Four studies evaluated safety and efficacy of EGD after MI. The reported complication rate ranged between 1-8%, with a large predominance of minor complications. We found one study addressing safety of flexible sigmoidoscopy that reported minor complications in two patients. We also identified one study addressing the safety of colonoscopy after MI, which showed a complication rate of 9%. Most of these complications were minor. A decision analysis was also included in this review. Conclusions: Our review demonstrated that endoscopic procedures are safe and beneficial in stable patients with GI bleeding after recent MI and should be performed without a requisite delay. Unstable patients should undergo endoscopic procedures only in the intensive care setting, after stabilization and with close monitoring. (Cardiol J 2012; 19, 5: 447-452

Low Molecular Weight Heparin in Atrial Fibrillation Management: Facts, Fiction, Future

Background: Atrial fibrillation (AF) is the most common sustained arrhythmia and various AF disease management strategies can be utilized.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/44690/1/10572_2004_Article_5264621.pd

Isthmus Dependent Atrial Flutter Cycle Length Correlates with Right Atrial Cross-Sectional Area

Background: Right atrial flutter cycle length can prolong in the presence of antiarrhythmic drug therapy. We hypothesized that the cycle length of right atrial isthmus dependent flutter would correlate with right atrial cross-sectional area measurements. Methods: 60 patients who underwent ablation for electrophysiologically proven isthmus dependent right atrial flutter, who were not on Class I or Class III antiarrhythmic drugs and had recent 2-dimensional echocardiographic data comprised the study group. Right atrial length and width were measured in the apical four chamber view. Cross-sectional area was estimated by multiplying the length and width. 35 patients had an atrial flutter rate ≥250 bpm (Normal Flutter Group) and 25 patients had an atrial flutter rate < 250 bpm (Slow Flutter Group). Results: Mean atrial flutter rate was 283 bpm in the normal flutter group and 227 bpm in the slow flutter group. Mean atrial flutter cycle length was 213 ms in the Normal Flutter Group and 265 ms in the Slow Flutter Group (p<0.0001). Mean right atrial cross sectional area was 1845 mm2 in the Normal Flutter group and 2378 mm2 in the Slow Flutter Group, (p< 0.0001). Using linear regression, CSA was a significant predictor of cycle length (β =0.014 p = 0.0045). For every 1 mm2 increase in cross-sectional area, cycle length is 0.014 ms longer.Conclusion: In the absence of antiarrhythmic medications, right atrial cross sectional area enlargement correlates with atrial flutter cycle length. These findings provide further evidence that historical rate-related definitions of typical isthmus dependent right atrial are not mechanistically valid

The value of diastolic function parameters in the prediction of left atrial appendage thrombus in patients with nonvalvular atrial fibrillation

BACKGROUND: Left ventricular diastolic impairment and consequently elevated filling pressure may contribute to stasis leading to left atrial appendage thrombus (LAAT) in nonvalvular atrial fibrillation (AF). We investigated whether transthoracic echocardiographic parameters can predict LAAT independent of traditional clinical predictors. METHODS: We conducted a retrospective cohort study of 297 consecutive nonvalvular AF patients who underwent transthoracic echocardiogram followed by a transesophageal echocardiogram within one year. Multivariate logistic regression analysis models were used to determine factors independently associated with LAAT. RESULTS: Nineteen subjects (6.4%) were demonstrated to have LAAT by transesophageal echocardiography. These patients had higher mean CHADS(2) scores [2.6 ± 1.2 vs. 1.9 ± 1.3, P = 0.009], higher E:e’ ratios [16.6 ± 6.1 vs. 12.0 ± 5.4, P = 0.001], and lower mean e’ velocities [6.5 ± 2.1 cm/sec vs. 9.1 ± 3.2 cm/sec, P = 0.001]. Both E:e’ and e’ velocity were associated with LAAT formation independent of the CHADS(2) score, warfarin therapy, left ventricular ejection fraction (LVEF), and left atrial volume index (LAVI) [E:e’ odds-ratio = 1.14 (95% confidence interval = 1.03 – 1.3), P = 0.009; e’ velocity odds-ratio = 0.68 (95% confidence interval = 0.5 – 0.9), P = 0.007]. Similarly, diastolic function parameters were independently associated with spontaneous echo contrast. CONCLUSION: The diastolic function indices E:e’ and e’ velocity are independently associated with LAAT in nonvalvular AF patients and may help identify patients at risk for LAAT

On-treatment comparison between corrective His bundle pacing and biventricular pacing for cardiac resynchronization: A secondary analysis of His-SYNC

Background The His-SYNC pilot trial was the first randomized comparison between His bundle pacing in lieu of a left ventricular lead for cardiac resynchronization therapy (His-CRT) and biventricular pacing (BiV-CRT), but was limited by high rates of crossover. Objective To evaluate the results of the His-SYNC pilot trial utilizing treatment-received (TR) and per-protocol (PP) analyses. Methods The His-SYNC pilot was a multicenter, prospective, single-blinded, randomized, controlled trial comparing His-CRT vs BiV-CRT in patients meeting standard indications for CRT (eg, NYHA II–IV patients with QRS >120 ms). Crossovers were required based on prespecified criteria. The primary endpoints analyzed included improvement in QRS duration, left ventricular ejection fraction (LVEF), and freedom from cardiovascular (CV) hospitalization and mortality. Results Among 41 patients enrolled (aged 64 ± 13 years, 38% female, LVEF 28%, QRS 168 ± 18 ms), 21 were randomized to His-CRT and 20 to BiV-CRT. Crossover occurred in 48% of His-CRT and 26% of BiV-CRT. The most common reason for crossover from His-CRT was inability to correct QRS owing to nonspecific intraventricular conduction delay (n = 5). Patients treated with His-CRT demonstrated greater QRS narrowing compared to BiV (125 ± 22 ms vs 164 ± 25 ms [TR], P < .001;124 ± 19 ms vs 162 ± 24 ms [PP], P < .001). A trend toward higher echocardiographic response was also observed (80 vs 57% [TR], P = .14; 91% vs 54% [PP], P = .078). No significant differences in CV hospitalization or mortality were observed. Conclusions Patients receiving His-CRT on-treatment demonstrated superior electrical resynchronization and a trend toward higher echocardiographic response than BiV-CRT. Larger prospective studies may be justifiable with refinements in patient selection and implantation techniques to minimize crossovers

Differential diagnosis of tachycardia with a typical left bundle branch block morphology

The evaluation of wide QRS complex tachycardias (WCT) remains a common dilemma for clinicians. Numerous algorithms exist to aid in arriving at the correct diagnosis. Unfortunately, these algorithms are difficult to remember, and overreliance on them may prevent cardiologists from understanding the mechanisms underlying these arrhythmias. One distinct subcategory of WCTs are those that present with a “typical” or “classic” left bundle branch block pattern. These tachycardias may be supraventricular or ventricular in origin and arise from functional or fixed aberrancy, bystander or participating atriofascicular pre-excitation, and bundle branch reentry. This review will describe these arrhythmias, illustrate their mechanisms, and discuss their clinical features and treatment strategies