The prognostic significance of atrial arrhythmias recorded early after cardioversion for atrial fibrillation

In a substantial number of patients, AF recurs after successful electrical cardioversion. The purpose of this study was to investigate if the atrial arrhythmias recorded immediately after cardioversion are associated with the risk of recurrence of the arrhythmia and to compare the prognostic significance of this parameter with that of other established risk factors. In a series of 71 patients, the risk factors for recurrence of AF during the first year after successful electrical cardioversion were analyzed. A new parameter that was investigated was the frequency of atrial premature beats and the presence of runs of supraventricular tachycardia in the Holter recording started immediately after the cardioversion. Age, left atrial size, left ventricular systolic function, duration of the arrhythmia before cardioversion, underlying cardiac disease, or medication taken were not found to be predictive of recurrence of the arrhythmia. However, the natural logarithm of the number of atrial premature complexes per hour of the Holter recording in the 37 patients in whom AF recurred was higher compared to that of the 34 patients who maintained sinus rhythm (P < 0.0005). The same was true if only the first 6 hours of the recording were analyzed (P < 0.0005). There was a trend for more frequent arrhythmia recurrence if runs of supraventricular tachycardia were present. The finding of > 10 atrial premature complexes per hour in the recording had a relative risk of 2.57 (1.51-4.37), a positive predictive accuracy of 76.5%, and a negative predictive accuracy of 70.3% for subsequent arrhythmia recurrence. We can conclude that frequent (> 10/hour) atrial premature complexes in the Holter recording after electrical cardioversion for AF is a significant risk factor for recurrence of the arrhythmia

Cardiac and sternocleidomastoid muscle involvement in Duchenne muscular dystrophy - An MRI study

Objective: To examine the extent of cardiac muscle and sternocleidomastoid muscle (SCM) involvement detected by MRI measurement of T2 relaxation time in patients with Duchenne muscular dystrophy (DMD) and no cardiorespiratory symptoms. Design: Prospective controlled study. Setting: Teaching referral hospital and university hospital. Subjects: Seventeen patients with DMD (age range, 7 to 25 years) and 17 age-matched control subjects. All patients were free of cardiac or respiratory complaints and had normal ECG, echocardiograph, and Holter monitor examination findings. Methods: We assessed respiratory function by means of standard pulmonary function testing. MRI measurements included the T2 relaxation time of the myocardium and the SCM in patients and control subjects. Results: The FVC and FEV1, values were lower in patients with DMD than in age-matched control subjects, whereas the FEV1/FVC ratio was normal in all subjects. Patients with DMD had lower T2 relaxation time of the heart (37.8 +/- 6.1 ms vs 58.1 +/- 7.1 ms, p < 0.001) and lower T2 relaxation time of the right SCM (24.5 +/- 2.6 ms vs 42.2 +/- 1.3 ms, p < 0.001) and left SCM (23.2 +/- 3.2 ms vs 42.2 +/- 1.6 ms, p < 0.001), compared to control subjects (+/- SD). In children (< 12 years of age), the T2 of the SCM was lower than that of the control subjects, but T2 of the heart id not differ between the two groups. In the patient group, T2 relaxation time of the heart decreased with age (r = - 0.80, p < 0.001). In patients with FVC < 80% of predicted, the T2 values of the heart were lower than the T2 values of patients with FVC 2: 80% of predicted (35.6 +/- 5.8 ms vs 41.8 +/- 4.6 ms, p < 0.05). Conclusions: MRI measurements of the T2 relaxation time in the myocardium and SCM of patients with DMD and no cardiorespiratory symptoms are abnormal, indicating altered tissue composition. These measurements may prove a clinically useful test for monitoring cardiac and respiratory muscle involvement in these patients

Pre-treatment with Irbesartan attenuates left atrial stunning after electrical cardioversion of atrial fibrillation

Aims: Left atrial (LA) stunning, the transient impairment of LA function, is responsible for an increased thrombo-embolic risk after cardioversion of atrial fibrillation (AF). Angiotensin receptor blockers (ARBs) attenuate atrial remodelling in AF and could theoretically influence LA stunning. We studied the effect of Irbesartan on LA stunning. Methods and results: We prospectively assigned 50 patients from the outpatient clinic undergoing electrical cardioversion for AF with duration of >4 weeks, into two matched groups: 25 patients were treated with Irbesartan (228 ± 93 mg/day) for at least 2 weeks prior to cardioversion (Irbesartan group); 25 patients did not receive ARBs (control group). The groups did not differ concerning age (64 ± 13 vs. 63 ± 13 years, respectively), AF duration (20 ± 18 vs. 20 ± 19 weeks), underlying disease, LA diameter (46±7 vs. 47 ± 9 mm), left ventricular dimensions, and ejection fraction (47.7 ± 11.6 vs. 49.7 ± 14.5%). We assessed LA appendage emptying velocities (LAAEV) and LA spontaneous echo contrast (LASEC) by transoesophageal echocardiography before and after cardioversion and at 2 weeks, and the A-wave by transthoracic echocardiography after cardioversion, at 2 and at 4 weeks. LA stunning was significantly attenuated in the Irbesartan group. The reduction of LAAEV immediately after cardioversion was significantly less in the Irbesartan group (LAAEV reduction of 9 ± 49% from 28 ± 9 cm/s before cardioversion to 25 ± 13 cm/s immediately afterwards) than in the control group (reduction of 48 ± 20% from 34 ± 15 cm/s before cardioversion to 16 ± 6 cm/s afterwards) (P = 0.048). New or increased LASEC occurred in eight patients (32%) in the Irbesartan vs. 16 patients (64%) in the control group (P=0.046). Conclusion: Irbesartan significantly attenuates LA stunning after electrical cardioversion of AF. Therefore, ARBs may represent an important pharmacological supplementation in patients being prepared for cardioversion. © The European Society of Cardiology 2006. All rights reserved

Overexpression of γ-tubulin in non-small cell lung cancer.

We and others have previously shown that increased expression and altered compartmentalization of γ-tubulin may contribute to tumorigenesis and tumor progression (J. Cell Physiol. 2009;223:519-529; Cancer Biol. Ther. 2010;9:66-76). Here we have determined by immunohistochemistry the localization and cellular distribution of γ-tubulin in clinical tissue samples from 109 non-small cell lung cancer (NSCLC) cases. The expression and distribution of γ-tubulin protein and transcripts was also determined in the NSCLC tumor cell lines NCI-H460 (HTB-177) and NCI-H69 (HTB-119) by immunocytochemistry, quantitative immunoblotting and reverse transcription quantitative real-time PCR (RT-qPCR). Polyclonal and monoclonal anti-peptide antibodies recognizing epitopes in the C- or N-terminal domains of γ-tubulins and human gene-specific primers for γ-tubulins 1 (TUBG1) and 2 (TUBG2) were used. In non-neoplastic cells of the airway epithelium in situ, γ-tubulin exhibited predominantly apical surface and pericentriolar localizations. In contrast, markedly increased, albeit heterogeneous and variously prominent γ-tubulin immunoreactivity was detected in clinical tumor specimens and in the NCI-H460 and NCI-H69 cell lines, where tumor cells exhibited overlapping multi-punctate and diffuse patterns of localization. Co-expression of γ-tubulin and Ki-67 (MIB-1) was detected in a population of proliferating tumor cells. A statistically significant increase of γ-tubulin expression was found in Stage III compared to lesser stage tumors (p<0.001 v. Stages I/II) regardless of histological subtype or grade. By quantitative immunoblotting NCI-H460 and NCI-H69 cells expressed higher levels of γ-tubulin protein compared to small airway epithelial cells (SAEC). In both tumor cell lines increase in TUBG1 and TUBG2 transcripts was detected by RT-qPCR. Our results reveal for the first time an increased expression of γ-tubulin in lung cancer

Level of patient and operator dose in the largest cardiac centre in Greece

The objective of this study was to investigate the patient and staff doses in the most frequent interventional cardiology (IC) procedures performed in Onassio, the largest Cardiac Centre in Greece. Data were collected from three digital X-ray systems for 212 coronary angiographies, 203 percutaneous transluminal coronary angioplasties (PTCA) and 134 various electrophysiological studies. Patient skin dose was measured using suitably calibrated slow radiotherapy films and cardiologist dose using suitably calibrated thermoluminescent dosemeters placed on left arm, hand and foot. Patient median dose area product (DAP) (all examinations) ranged between 6.7 and 83.5 Gy cm2. Patient median skin dose in PTCA was 799 mGy (320-1660 mGy) and in RF ablation 160 mGy (35-1920 mGy). Median arm, hand and foot dose to the cardiologist were 12.6, 27 and 13 μSv, respectively, per procedure. The great range of radiation doses received by both patients and operators confirms the need for continuous monitoring of all IC techniques. © The Author 2008. Published by Oxford University Press. All rights reserved

Atrial fibrillation in recipients of cardiac resynchronization therapy device: 1-year results of the randomized MASCOT trial

Background: Atrial fibrillation (AF) is associated with increased morbidity and mortality in patients suffering from heart failure (HF). Patients in New York Heart Association HF classes III or IV, with systolic dysfunction and a wide QRS, are candidates for cardiac resynchronization therapy (CRT), and might benefit from atrial overdrive pacing (AOP). Methods: The Management of Atrial fibrillation Suppression in AF-HF COmorbidity Therapy (MASCOT) trial enrolled 409 CRT device recipients (79% men), who were randomly assigned to AOP ON (n = 197), versus AOP OFF (n = 197) and followed up for 1 year. Their mean age was 68 ± 10 years, left ventricular ejection fraction 25 ± 6%, QRS duration 163 ± 29 milliseconds. New York Heart Association class III was present in 86% of patients and 19% had a history of paroxysmal AF. The primary study end point was incidence of permanent AF at 1 year. Results: Atrial overdrive pacing increased the percentage of atrial pacing from 30% to 80% (P < .0001), was well tolerated, and did not interfere with (a) delivery of CRT (95% mean ventricular pacing in both groups), (b) response to CRT (70% responders in the control vs 67% in the treatment group), or (c) cardiac function (left ventricular ejection fraction increased from 24.5% ± 6.2% to 32.7% ± 10.9% in the control and from 25.8% ± 6.8% to 33.1% ± 12.6% in the treatment group). The incidence of permanent AF was 3.3% in both groups. By logistic regression analysis, a history of AF (P < .001) and absence of antiarrhythmic drugs (P = .002) were associated with permanent AF. Conclusions: In this first trial of a specific AF prevention algorithm in CRT recipients, AOP was safe and did not worsen HF. The prevention algorithm did not lower the 1-year incidence of AF. © 2008 Mosby, Inc. All rights reserved