Idiopathic ventricular arrhythmias originating from the moderator band: Electrocardiographic characteristics and treatment by catheter ablation.

BACKGROUND: The moderator band (MB) can be a source of premature ventricular contractions (PVCs), monomorphic ventricular tachycardia (VT), and idiopathic ventricular fibrillation (IVF). OBJECTIVE: The purpose of this study was to define the electrocardiographic (ECG) characteristics and procedural techniques to successfully identify and ablate MB PVCs/VT. METHODS: In 10 patients with left bundle branch block morphology PVCs/VT, electroanatomic mapping in conjunction with intracardiac echocardiography (ICE) localized the site of origin of the PVCs to the MB. Clinical characteristics of the patients, ECG features, and procedural data were collected and analyzed. RESULTS: Seven patients presented with IVF and 3 presented with monomorphic VT. In all patients, the ventricular arrhythmias (VAs) had a left bundle branch block QRS with a late precordial transition (>V4), a rapid downstroke of the QRS in the precordial leads, and a left superior frontal plane axis. Mean QRS duration was 152.7 ± 15.2 ms. Six patients required a repeat procedure. After mean follow-up of 21.5 ± 11.6 months, all patients were free of sustained VAs, with only 1 patient requiring antiarrhythmic drug therapy and 1 patient having isolated PVCs no longer inducing VF. There were no procedural complications. CONCLUSION: VAs originating from the MB have a distinctive morphology and often are associated with PVC-induced ventricular fibrillation. Catheter ablation can be safely performed and is facilitated by ICE imaging.

Atrial fibrillation following autologous stem cell transplantation in patients with multiple myeloma: incidence and risk factors.

OBJECTIVES: Atrial fibrillation (AF) often develops in patients with multiple myeloma following autologous stem cell transplantation (ASCT), but the exact incidence of, and the risk factors for AF have not been described. In this study, we sought to determine the incidence of AF in patients with multiple myeloma undergoing ASCT. METHODS: Patients who received ASCT for multiple myeloma between January 2000 and December 2009 were identified using the ICD-9 codes for multiple myeloma and ASCT, and formed the basis of this report. RESULTS: The study included 278 patients (mean age, 63 ± 9.5 years). A total of 75 (27%) patients developed AF at a mean duration of 14.8 days following ASCT. On multiple regression analysis, baseline renal dysfunction (odds ratio 15.2 [confidence interval 5.08-45.6]), left ventricular systolic dysfunction (9.55 [2.78-32.79]), dilated left atrium on echocardiogram (4.97 [1.8-13.78]), and hypertension (3.6 [1.36-9.52]) were significantly associated with the development of AF after ASCT. The presence of light-chain secretion (0.21 [0.07-0.6]) was associated with a lower incidence of AF. Age, gender, and race were not significantly associated with the development of AF after ASCT. CONCLUSIONS: AF is very frequent in patients with multiple myeloma when they receive ASCT. The presence of abnormal renal function, left ventricular systolic dysfunction, dilated left atrium, or hypertension at baseline identifies patients at high risk of developing AF following ASCT.

A patient with mexiletine-related psychosis.

Mexiletine is a commonly used Class IB (Vaughan William classification) antiarrhythmic drug. We report a case of mexiletine-induced psychosis that was successfully managed by decreasing the dose and using alternative medications for management of ventricular tachycardia.

Assessment of left ventricular function: comparison of cardiac multidetector-row computed tomography with two-dimension standard echocardiography for assessment of left ventricular function.

OBJECTIVE: To compare global Left Ventricular (LV) systolic function assessment by 16-detector row Computed Tomography (MDCT) with Two-Dimensional Standard Echocardiography (2DSE) in a routine cardiology practice setting and to ascertain the degree of correlation between LV volumes and measurements obtained by 2DSE with those measured by MDCT. METHODS: In 52 patients with suspected coronary artery disease, a contrast enhanced MDCT study was performed using retrospective gating without dose modulation for better endocardial delineation. Eight phases of the cardiac cycle were analyzed to identify the end-diastolic and end-systolic phases. 2DSE was performed on the same day. Left ventricular systolic and diastolic volumes and ejection fraction were calculated in 4-chamber, 2-chamber and biplane (average of the two) views. Endocardial tracing was used to measure ventricular volumes by area length method for CT and Simpson's method for echocardiography. RESULTS: On MDCT, mean LV ejection fraction (LVEF) in 4-chamber, 2-chamber and biplane views were 58.4 +/- 12, 59.3 +/- 12 and 59.7 +/- 12% respectively. On 2DSE, mean LVEF in 4-chamber, 2-chamber and biplane views were 58 +/- 14, 57 +/- 16 and 58 +/- 13% respectively. LVEF correlated best using the biplane views (r = 0.59 and P < 0.01) compared to 2-chamber (r = 0.57 and P < 0.01) and 4-chamber views (r = 0.32 and P = 0.02). Biplane measurement by these two techniques correlated well for LV volumes in both diastole (r = 0.69 and P < 0.01) and systole (r = 0.73 and P < 0.01), although MDCT consistently gave higher values. CONCLUSIONS: MDCT can be a useful tool to measure LVEF while patients are undergoing CT coronary angiography.

Predictors of in-stent restenosis and patient outcome after percutaneous coronary intervention in patients with diabetes mellitus.

Diabetics have a significantly higher incidence of major adverse cardiac events (MACEs) and in-stent restenosis (ISR) than nondiabetics after percutaneous coronary intervention (PCI). Predictors of MACEs and ISR are uncertain in diabetics. In recent studies, microalbuminuria and proliferative retinopathy have been believed to relate to progressive coronary atherosclerosis. We retrospectively studied 191 consecutive patients (mean age 65 +/- 9 years) with diabetes who underwent PCI to determine predictors of ISR and MACEs (defined as cumulative incidence of myocardial infarction, revascularization, or death from cardiovascular cause), with special reference to microalbuminuria and proliferative retinopathy. Of 191 patients, 106 (56%) had a follow-up coronary angiogram at 16 +/- 2 months. Of these 106 patients, 66 (62%) developed ISR. In the multivariate model, microalbuminuria or proliferative retinopathy did not achieve significant association with ISR. Serum high-density lipoprotein cholesterol levels were significantly associated with a lower incidence of ISR (odds ratio [OR] 0.928, 95% confidence interval [CI] 0.876 to 0.983, p = 0.011) and MACEs (OR 0.96, 95% CI 0.931 to 1.000, p = 0.048). Use of drug-eluting stents also had a negative association with ISR (OR 0.171, 95% CI 0.05 to 0.585, p = 0.004). Renal insufficiency was associated with higher MACEs (OR 3.19, 95% CI 1.45 to 7.031, p = 0.0039). In conclusion, serum high-density lipoprotein cholesterol levels were inversely associated with ISR or MACEs.

Use of clopidogrel in coronary artery disease.

Clopidogrel has an established and important role in the management of patients with coronary artery disease after an acute event. It is generally a well-tolerated drug. The major common problem associated with its use is the increased incidence of bleeding complications during or after coronary artery bypass graft surgery when clopidogrel is used within five days before surgery. For this reason, it is recommended to stop clopidogrel at least five days, and preferably one week before surgery.