Acute Modifications of Left Ventricular Torsional Mechanics Induced by Cardiac Resynchronization Therapy Affect Short-Term Reverse Remodeling.

BACKGROUND: Left ventricular (LV) torsion is an important aspect of cardiac mechanics and is altered in heart failure patients. Cardiac resynchronization therapy (CRT) has a positive effect on LV function, but the exact mechanisms through which it works are not completely depicted. Our aim was to investigate (1) the acute CRT effect on LV torsional mechanics in heart failure patients using 3D speckle tracking echocardiography (3DSTE) and (2) its effect on short-term LV remodeling. Methods and Results: We considered 48 patients (age 72±11 years, 35 men) who received CRT. They underwent 3DSTE during CRT-on (biventricular stimulation) vs. CRT-off (intrinsic conduction/right atrial/ventricular stimulation alone), in a random fashion. Patients were classified as CRT responders based on LV systolic volume reduction ≥15% at 6 months (final population: 31 responders, 17 non-responders). Acute CRT positively affected responders in terms of LV torsion (from 0.32±0.06°/cm CRT-off to 0.41±0.06°/cm CRT-on), but adversely affected non-responders (from 0.54±0.08°/cm CRT-off to 0.28±0.08°/cm CRT-on, interaction P=0.02). A similar trend was confirmed for apical (interaction P<0.04), but not for basal torsion (interaction P=0.351). CONCLUSIONS: CRT has a positive role in acute recovery of LV torsion (particularly in its apical component) in responders, likely modulating the improvement in LV remodeling at early follow-up.

Predictors of mortality and hospitalization for cardiac causes in patients with heart failure and nonischemic heart disease: a subanalysis of the ALPHA study.

BACKGROUND: Several studies have searched for predictors of clinical outcome in patients with heart failure (HF). However, since they were collected in clinical trials, most data were subject to selection biases and do not specifically apply to patients with nonischemic heart disease. This study examined the impact of several variables on combined all-cause mortality and hospitalization for cardiac causes, in consecutive ambulatory patients with HF included in the ALPHA registry. METHODS AND RESULTS: This analysis included 446 patients with HF and nonischemic heart disease, in New York Heart Association functional class II or III, and a left ventricular (LV) ejection fraction below 40%. In 126 patients (73%) the disease was idiopathic dilated cardiomyopathy, in 72 (16%) hypertensive, in nine (2%) valvular, and in 39 (9%) of other etiologies. The median age was 61 years (range 51-69 years) and 349 (78%) patients were men. Over a median follow-up of 31 months (range 23-40), 82 patients (18%) died or were hospitalized for cardiac causes. In a proportional hazard (Cox) regression model, maximal oxygen consumption (HR 0.9, P = 0.001), LV end-diastolic diameter (HR 1.07, P < 0.001), resting systolic blood pressure (HR 0.97, P < 0.005), and hemoglobin (HR 0.86, P < 0.05) were independent predictors of the combined study endpoint. CONCLUSIONS: In an unselected population of patients with HF and nonischemic heart disease, a reduced exercise capacity, large LV end-diastolic diameter, low systolic blood pressure, and hemoglobin were correlated with long-term all-cause mortality or hospitalization for cardiac causes. These observations may help stratifying and tailoring the treatment of patients with HF and nonischemic heart disease.

Atrial fibrillation in heart failure patients: prevalence in daily practice and effect on the severity of symptoms. Data from the ALPHA study registry.

BACKGROUND: Estimates of the prevalence of atrial fibrillation (AF) in heart failure (HF) originate from patients enrolled in clinical trials. AIMS: To assess the prevalence and clinical correlates of AF among HF patients in everyday clinical practice from HF patients screened for the T-wave ALternans in Patients with Heart fAilure (ALPHA) study; to investigate the correlation between AF and functional status. METHODS AND RESULTS: Consecutive patients (N=3513) seen at nine Heart Failure Clinics were studied; 21.4% were in AF. AF prevalence was greater with increasing age (OR 1.04/year, p<0.001) in non-ischaemic cardiomyopathy (OR 2.34, p<0.001) and with increasing NYHA class (p<0.0001). Multiple logistic regression predictors of AF were age >70 years (OR 2.35), NYHA class II III or IV vs class I (OR 1.8, 4.4 and 3.1) and non-ischaemic cardiomyopathy (OR 3.2). A logistic model indicated that AF was associated with a 2.5 OR of being in NYHA class III-IV vs I-II while accounting for age, gender, left ventricular ejection fraction (LVEF), and aetiology of HF. CONCLUSIONS: The prevalence of AF in HF patients exceeds 20%, and increases with age and functional class. The presence of AF leads to a more severe NYHA class, indicating that AF contributes to the severity of heart failure.

Cardiac dyssynchrony quantitated by time-to-peak or temporal uniformity of strain at longitudinal, circumferential, and radial level: implications for resynchronization therapy.

BACKGROUND: The standard deviation of time to peak strain (TPS-SD) has been proposed as an index of left ventricular (LV) dyssynchrony in patients to be resynchronized. However, TPS-SD is sensitive to noise, and the influence of outliers on TPS-SD is also relevant. Alternatively, dyssynchrony can be indexed by temporal uniformity of strain (TUS), whereby a time plot of regional strains, arranged for LV location, is subjected to Fourier analysis. If segments shorten simultaneously (synchronously), the plot appears as a straight line, with power only in the zero-order Fourier term, whereas regionally clustered dyssynchrony generates an undulating plot with higher power in the first-order term. TUS index reflects zero-order relative to first-order plus zero-order power. METHODS: In this study, TUS and TPS-SD were computed in 68 patients (QRS duration >/= 120 ms; ejection fraction

Left ventricular torsion in paced patients.

BACKGROUND: In healthy people the left ventricle presents a counter-clockwise apical rotation and a clockwise basal rotation ending in late systole. In early systole (during isovolumic contraction) there is a fast and inverse rotation (counter-clockwise at the base and clockwise at the apex). This opposite rotation between apex and base produces the systolic torsion of the left ventricle. The effect of permanent conventional pacing on this torsion is little known. OBJECTIVES: The aim of this study was to assess, by speckle tracking echocardiography, left ventricular rotation and torsion in patients conventionally paced at the apex of the right ventricle. METHODS: Left ventricular apical and basal rotation and the consequent torsion were evaluated by means of speckle tracking echocardiography, in 13 paced patients, without ischemic or valvular disease, and in 17 healthy participants. Left ventricular dyssynchrony was evaluated by means of temporal uniformity of strain. RESULTS: In the paced group there was a significant reduction in early-systolic clockwise torsion (-0.4 degrees +/- 1.2 vs. -1.5 degrees +/- 1.6; P = 0.04), and in late-systolic counter-clockwise torsion (15.1 degrees +/- 4.3 vs. 19.1 degrees +/- 5.5; P = 0.03). Circumferential temporal uniformity of strain averaged significantly lower in paced patients. CONCLUSIONS: Conventional pacing from the apex of the right ventricle alters both the torsional mechanic and the synchrony of the left ventricle.

[Electrical storms in patients with implantable cardioverter-defibrillator: incidence and clinical management]. / La tempesta aritmica nel paziente con defibrillatore automatico impiantabile: incidenza e problematiche terapeutiche.

BACKGROUND: Electrical storm in implantable cardioverter-defibrillator (ICD) recipients is a dramatic experience for the patient and a hard emergency for the cardiology team. The aim of our study was to evaluate the incidence and the clinical significance of electrical storm in a standard population of ICD patients. METHODS: We considered retrospectively 262 consecutive ICD patients (86% males, mean age 65+/-10.7 years). Patients were divided into three groups: 88 patients without appropriate ICD therapy (group A); 140 patients with isolated ICD therapies (group B); 34 patients with electrical storm episodes (> or = 3 appropriate ICD therapies/24 h) (group C). Survival study (endpoint death) was performed for each group of patients. RESULTS: There was no difference in age, sex, heart disease, ejection fraction or NYHA functional class among the three groups. ICD implant was performed for secondary prevention in 79% of group C patients and in 74.3 % of group B patients, but only in 39.8 % of group A patients (p < 0.0001). Mean follow-up was 31.1+/-29.8 months in group A, 55.1+/-38 months in group B, and 71.1+/-51.7 months in group C. The endpoint was reached by 16 patients (18%) of group A, by 53 patients (38%) of group B, and by 20 patients (58%) of group C. Comparison of the survival curves of the three groups did not show significant differences. In group C patients, 54 electrical storm episodes were recorded (mean 1.5/patient). CONCLUSIONS: In our population of ICD patients, we observed electrical storm in 34 patients (12.9%). Survival in group with episodes of electrical storm was comparable to patients without electrical storm; thus, in our experience, electrical storm could not represent a negative prognostic factor.