Brugada syndrome ECG pattern and fever: too warm is bad.

We describe a case of Brugada syndrome disclosed by fever and with non-significant alterations after a flecainide test.

Persistent left superior vena cava and pacemaker implantation.

Our study group read with interest the paper from Vijayvergiya et al describing the implantation of an implantable cardioverter-defibrillator lead in the presence of the persistence of the left superior vena cava. The issue of the identification a persistent left superior vena cava is of paramount importance in interventional cardiology, being the most common venous anomaly of the thoracic distribution, and because it may create some problem to any physician while performing a pacemaker lead implantation. In our letter we underscore the specific issues related to pacemaker implantation while encountering a persistent left superior vena cava (and maybe the absence of the right vena cava) and the workup that should be performed to obtain the preoperative diagnosis of the venous anomaly. More specifically, we consider avoiding any kind of defibrillator lead implantation through the coronary sinus for safety issues, and underscore the straightforward transthoracic ultrasound approach to identify the left superior vena cava.

Effectiveness of cardiac resynchronisation therapy in patients with echocardiographic evidence of mechanical dyssynchrony.

OBJECTIVE: Cardiac resynchronisation therapy has proven to be effective in refractory heart failure (HF) patients with QRS >120-130 ms. Therefore, the aim of our study was to verify the long-term effectiveness of cardiac resynchronisation therapy in HF patients with echocardiographic evidence of mechanical asynchrony regardless of QRS duration. METHODS: One hundred and six patients with New York Heart Association class II-IV HF and echocardiographic documentation of interventricular and intraventricular asynchrony underwent biventricular stimulation. A clinical and functional evaluation was performed at baseline, 1, 3, 6 months, and every 6 months thereafter. RESULTS: After a median follow-up of 16 months, a significant improvement was noted in ejection fraction, left ventricular diameters, mitral regurgitation jet area, interventricular and intraventricular echocardiographic indexes of asynchrony, and the 6-min walking distance (P < 0.001 for all). Death rates for all causes and for cardiac causes were 18.2 (95% confidence interval 12.8-25.9) and 13.5 (95% confidence interval 9.0-20.3) per 100 person-years, respectively. Patients in New York Heart Association class IV had an almost three-fold increase in risk of dying as compared to class II-III (hazard ratio 2.97, 95% confidence interval 1.30-6.79). CONCLUSIONS: Interventricular and intraventricular asynchrony at echocardiography may be useful in identifying HF patients suitable for cardiac resynchronisation therapy, with results comparable to those obtained with QRS duration selection criteria.

Brugada syndrome and neurally mediated susceptibility.

The risk of sudden death in patients with Brugada syndrome (BS) is still unclear. Moreover, particular clinical conditions may have a confounding effect on the diagnostic and therapeutic approach. We report the case of a 27-year-old man with a clinical history of suspected neurally mediated syncope and typical ECG features of BS. The tilt table test showed a type I, mixed, positive response. The electrophysiological study (EPS) disclosed a peculiar ventricular irritability with the induction of a life-threatening arrhythmia. After the implantation of a cardioverter-defibrillator an episode of ventricular fibrillation during sleep at night was correctly identified and treated by the device. The association between neurally mediated susceptibility and the typical ECG abnormalities of BS is not an unexpected event in young subjects. The misjudgment of the pathophysiological mechanism of syncopal episodes may lead, on one hand, to overlook the risk of sudden death and, on the other, to pursue inappropriate therapeutic measures. The application of a tailored diagnostic work-up based on currently available guidelines may be useful to overcome the clinical and therapeutic dilemma.

[Cardiac resynchronization therapy for heart failure]. / La terapia di resincronizzazione cardiaca per il trattamento dello scompenso cardiaco.

The short-term prognosis of advanced refractory heart failure is extremely poor and closely correlated with progressive left ventricular dysfunction. The identification of the negative effects of conduction delay on cardiac performance, observed in almost 50% of heart failure patients, disclosed a new research field addressing the correction of electrical abnormalities in order to achieve an improvement in myocardial function. Biventricular stimulation, or cardiac resynchronization therapy, corrects the atrioventricular, inter- and intraventricular mechanical asynchrony and, to date, is indicated (class IIA, level of evidence A) for patients with NYHA class III-IV refractory heart failure regardless of its etiology, QRS interval > or = 130 ms, left ventricular end-diastolic diameter > or = 55 mm, and ejection fraction < or = 35%. To date, the completed trials demonstrated in patients undergoing biventricular pacing a significant improvement in left ventricular performance, quality of life and NYHA class with no significant effects on total mortality. The identification of non-responders (approximately 20-30% of the patient population in completed trials) represents an unresolved issue of cardiac resynchronization therapy. Tissue Doppler imaging evaluation of left ventricular dyssynchrony, which is being addressed by non-randomized prospective studies, should drastically decrease the percentage of these patients.

Long-term effectiveness of cardiac resynchronization therapy in patients with refractory heart failure and "narrow" QRS.

OBJECTIVES: The aim of the study was to evaluate the effectiveness of cardiac resynchronization therapy (CRT) in patients with refractory heart failure (HF) and incomplete left bundle branch block ("narrow" QRS), together with echocardiographic evidence of interventricular and intraventricular asynchrony. BACKGROUND: Cardiac resynchronization therapy has been proven effective in patients with HF and wide QRS by ameliorating contraction asynchrony. METHODS: Fifty-two patients with severe HF received biventricular pacing. The patients were eligible in the presence of echocardiographic evidence of interventricular and intraventricular asynchrony, regardless of QRS duration. The patient population was divided into group 1 (n = 38), with a QRS duration >120 ms, and group 2 (n = 14), with a QRS duration < or =120 ms. RESULTS: The baseline parameters considered in the study were similar in both groups. At follow-up, CRT determined narrowing of the QRS interval in the entire population and in group 1 (p < 0.001), whereas a small increase in QRS duration was observed in group 2 (p = NS); in all patients and within groups, we observed improvement of New York Heart Association functional class (p < 0.001 in all), left ventricular ejection fraction (p < 0.001 in all), left ventricular end-diastolic and end-systolic diameter (p < 0.05 within groups), mitral regurgitation area (p < 0.001 in all), interventricular delay (p < 0.001 in all), and deceleration time (group 1: p < 0.001, group 2: p < 0.05), with no significant difference between groups. The 6-min walking test improved in both groups (group 1: p < 0.001; group 2: p < 0.01). CONCLUSIONS: Cardiac resynchronization therapy determined clinical and functional benefit that was similar in patients with wide or "narrow" QRS. Cardiac resynchronization therapy may be helpful in patients with echocardiographic evidence of interventricular and intraventricular asynchrony and incomplete left bundle branch block.

Comparison of two different methods for the evaluation of left ventricular ejection fraction in patients with coronary artery disease.

The evaluation of left ventricular ejection fraction (LVEF) may be troublesome in difficult clinical settings in patients with coronary artery disease (CAD). The aim of this study was to compare 2 simple geometrical and nongeometrical methods of LVEF evaluation that could overcome the typical technical limitations of ultrasound examination. The authors studied 26 patients with proven CAD (63+/-10 years) who underwent left ventricular (LV) catheterization and coronary angiography during the hospital stay. A complete 2D-Doppler echocardiography was performed and LVEF was evaluated with the formula by Wyatt (W-LVEF), which relates the left ventricle to a biplane ellipsoidal figure, and by the myocardial performance index (MPI) formula (MPI-LVEF), MPI being an index of systodiastolic function. Mean MPI-LVEF was 41+/-8% and was significantly lower with respect to contrast angiography (52+/-14%, p = 0.0003) and to W-LVEF (49+/-13%, p = 0.0009). There was no statistically significant correlation between MPI-LVEF and geometric (either angiographic or ultrasound) LVEF. Bland-Altman analysis showed lack of agreement between MPI-LVEF and any other method evaluated in the study. MPI-LVEF may not be reliable and accurate for the evaluation of systolic function in patients with CAD. Nonetheless, the evaluation of global LV function by means of MPI may represent a valuable and affordable alternative to expensive and time-consuming methods, especially in the presence of difficult technical settings.