Wide-QRS-complex tachycardia with a negative concordance pattern in the precordial leads: Are the ECG criteria always reliable?

We present a case of wide-complex tachycardia with negative concordance in the precordial leads and a qR pattern in V6, in a 42-year-old man with risk factors for coronary artery disease, in whom the electrocardiogram criteria were apparently fallible. This case highlights the key contribution of the electrophysiological study in rendering correct diagnosis.

Ivabradine: a selective If current inhibitor in the treatment of stable angina.

The role of heart rate reduction in the management of myocardial ischemia and chronic stable angina is pivotal. However, broad use and appropriate dosing of commonly used rate-slowing drugs is limited by their poor tolerability. Ivabradine is a selective inhibitor of the If currents of the sinoatrial node cells. If currents activity determines the slope of the depolarization curve towards the threshold level controlling heart rate in patients with sinus rhythm. Ivabradine, a compound of the benzocyclobutane (S 16257), exhibits a unique specificity for the If current and has a more favorable profile of adverse reactions compared to other If inhibitors. Accordingly, ivabradine has been used in the treatment of stable angina, where it presented anti-anginal and anti-ischemic effects equivalent to the effects of atenolol and amlodipine. Clinical studies proved the efficacy of ivabradine in patients with stable angina, while clinical data are awaited to verify its probable value in the treatment of atrial tachyarrhythmias and tachycardia due to ventricular dysfunction. Thus, the clinical value of ivabradine, which has completed clinical development for stable angina, is expected to exceed its role in the treatment of myocardial ischemia. In this context, ivabradine, promising efficacious and safe pharmacological management of heart rate, is a huge step in cardiovascular therapeutics.

Right ventricle bipolar pacing may prevent appropriate biventricular pacing from two pacemakers. Case report.

This article reports on practical problems and possible solutions that may occur in case of upgrading a dual-chamber pacemaker by implanting a second left ventricular ventricular pacing, ventricular sensing, ventricular triggering (VVT) pacemaker. This therapeutic strategy was considered appropriate in the case of a 73-year-old patient with severe heart failure, who was scheduled to undergo coronary artery bypass surgery. A right-sided, dual-chamber pacemaker had been already implanted to the patient. The duration of the paced QRS complex was 220 ms and inter- and intraventricular dyssynchrony was documented in the echocardiographic study. We describe the methodological problems and possible solutions related to biventricular pacing following the abovementioned strategy.

The Contribution of the Left Atrioventricular Plane Displacement During Low Dose Dobutamine Stress Echocardiography in Predicting Recovery of Left Ventricular Dyssynergies.

The aim of this study was to assess the significance of the left systolic atrioventricular (AV) plane displacement during low dose dobutamine stress echocardiography (DSE), in predicting the recovery of left ventricular dyssynergies after revascularization. In 30 infarctiers with left ventricular dysfunction scheduled for RE (14 percutaneous transluminal coronary angioplasty and 16 coronary artery bypass graft) and in 25 age- and sex-matched healthy subjects, a DSE, using a 16 ventricular segment model and a four-grade scoring system for the assessment of regional wall motion of the left ventricle was performed. Prior and during DSE, the left systolic AV plane displacement was recorded from the apical four- and two-chamber views, by M-mode echo, at four left ventricular sites, corresponding to the septal, lateral, anterior, and inferior walls, both in patients and controls. The study was repeated in all patients 101 +/- 14 days after successful revascularization. Healthy subjects showed a significant increase of left systolic AV plane displacement at all left ventricular sites during dobutamine infusion (DI) (P < 0.001). Patients also exhibited a significant maximum increase of left systolic AV plane displacement during DSE only in the dyssynergic sites with functional improvement in the postrevascularization echocardiogram (P < 0.001). In the remaining dyssynergic sites, without functional improvement after revascularization, the left systolic AV plane displacement did not change (P > 0.05). Selecting a maximum LAVPD increase of >2 mm at any site of the left ventricule to predict recovery of the regional ventricular dyssynergies, results in a sensitivity of 91%, specificity of 83%, positive predictive value of 88%, and negative predictive value of 87%. When two-dimensional DSE was used for the detection of reversible dysfunction, sensitivity and specificity were found to be 81.5% and 87.5%, respectively, while the positive and negative predictive values were 90% and 78%, respectively. When the two methods were in agreement the sensitivity was 90%, the specificity 100%, and the positive and negative predictive values were 100% and 84.2%, respectively. The assessment of left systolic AV plane displacement during DI constitutes a new, simple, and accurate method in the prediction of left ventricular dyssynergy recovery after revascularization. The combination of this method and two-dimensional DSE are basic predictor markers of viability of dysfunctional myocardium. (ECHOCARDIOGRAPHY, Volume 13, November 1996)