The aims of the present study were to investigate the incidence and characteristics of conduction disorders (CDs) after transcatheter aortic valve implantation (TAVI), to analyze the predictors of ...permanent pacemaker (PPM) implantation, and to evaluate the outcomes of CDs over time. In particular, we sought to investigate whether the depth of deployment and other technical aspects of valve implantation might predict the need for PPM implantation after TAVI. TAVI has been reported to favor the onset or worsening of CDs often requiring PPM implantation. A total of 70 patients with aortic stenosis due to dystrophic calcification underwent TAVI with third-generation CoreValve Revalving System from May 2007 to April 2009. We collected electrocardiograms at baseline, during TAVI, during hospitalization and at the 1-, 3-, 6-, and 12-month follow-up visits thereafter. The clinical, anatomic, and procedural variables were tested to identify the predictors of PPM implantation. The PPM dependency at follow-up was analyzed. Six patients were excluded from the analysis because of a pre-existing PPM. Of the 64 patients, 32 (50%) had one or more atrioventricular-intraventricular CDs at baseline. TAVI induced a worsening in the CDs in 49 (77%) of the 64 patients, with 25 (39%) requiring in-hospital PPM implantation. On multivariate analysis, the independent predictors of PPM implantation were the depth of the prosthesis implantation (p = 0.039) and the pre-existing right bundle branch block (p = 0.046). A trend in the recovery of the CDs over time was recorded, although 2 patients required PPM implantation 1 month after discharge for late complete atrioventricular block. In conclusion, TAVI often induces or worsens CDs, requiring PPM in more than one third of patients, although a trend in the recovery of CDs during the midterm was recorded. The independent predictors of PPM implantation were the depth of prosthesis implantation and pre-existing right bundle branch block.
Current risk stratification for sudden cardiac death (SCD) in nonischemic dilated cardiomyopathy (NIDC) relies on left ventricular (LV) dysfunction, a poor marker of ventricular electrical ...instability. Contrast-enhanced cardiac magnetic resonance has the ability to accurately identify and quantify ventricular myocardial fibrosis (late gadolinium enhancement LGE).
To evaluate the impact of the presence and amount of myocardial fibrosis on arrhythmogenic risk prediction in NIDC.
One hundred thirty-seven consecutive patients with angiographically proven NIDC were enrolled for this study. All patients were followed up for a combined arrhythmic end point including sustained ventricular tachycardia (VT), appropriate implantable cardioverter-defibrillator (ICD) intervention, ventricular fibrillation (VF), and SCD.
LV-LGE was identified in 76 (55.5%) patients. During a median follow-up of 3 years, the combined arrhythmic end point occurred in 22 (16.1%) patients: 8 (5.8%) sustained VT, 9 (6.6%) appropriate ICD intervention, either against VF (n = 5; 3.6%) or VT (n = 4; 2.9%), 3 (2.2%) aborted SCD, and 2 (1.5%) died suddenly. Kaplan-Meier analysis revealed a significant correlation between the LV-LGE presence (not the amount and distribution) and malignant arrhythmic events (P < .001). In univariate Cox regression analysis, LV-LGE (hazard ratio HR 4.17; 95% confidence interval CI 1.56-11.2; P = .005) and left bundle branch block (HR 2.43; 95% CI 1.01-5.41; P = .048) were found to be associated with arrhythmias. In multivariable analysis, the presence of LGE was the only independent predictor of arrhythmias (HR 3.8; 95% CI 1.3-10.4; P = .01).
LV-LGE is a powerful and independent predictor of malignant arrhythmic prognosis, while its amount and distribution do not provide additional prognostic value. Contrast-enhanced cardiac magnetic resonance may contribute to identify candidates for ICD therapy not fulfilling the current criteria based on left ventricular ejection fraction.
Recent European Association of Echocardiography and American Society of Echocardiography guidelines on three-dimensional echocardiography state that normal values of left ventricular (LV) parameters ...for age and body size remain to be established.
In 226 consecutive healthy subjects (125 women; age range, 18-76 years), comprehensive three-dimensional echocardiographic analyses of LV parameters were performed, and values were compared with those obtained by conventional echocardiography.
Upper reference values (mean+ 2 SDs) for three-dimensional LV end-diastolic and end-systolic volumes were 85 and 34 mL/m(2) in men and 72 and 28 mL/m(2) in women, respectively. Indexing LV volumes to body surface area did not eliminate gender differences. Lower reference values (mean - 2 SDs) for ejection fraction were 54% in men and 57% in women and for stroke volume were 25 and 24 mL/m(2), respectively. Upper reference values for LV mass were 97 g/m(2) in men and 90 g/m(2) in women and for end-diastolic sphericity index were 0.49 and 0.48, respectively. Significant age dependency of LV parameters was identified and reported across age groups. Three-dimensional echocardiographic LV volumes were larger, ejection fraction was similar, and LV stroke volume and mass were significantly smaller in comparison with the corresponding values obtained by conventional echocardiography.
The investigators report a comprehensive analysis of LV geometry and function using three-dimensional echocardiography in a relatively large cohort of healthy Caucasian subjects with a wide age range. These may serve to establish age-specific and gender-specific reference ranges, which are crucial for the routine implementation of three-dimensional echocardiography to detect LV remodeling and dysfunction in clinical practice.
Left atrial (LA) longitudinal strain (LS) using two-dimensional speckle-tracking echocardiography has emerged as an important diagnostic and prognostic parameter in various cardiovascular conditions. ...However, its reference values, their correlations with demographics characteristics, and its physiologic determinants remain to be established.
Accordingly, 171 healthy volunteers (mean age, 45 ± 12 years; 61% women) in whom LS was obtained from both apical four- and two-chamber dedicated views of the left atrium, considering the P-P interval on the electrocardiogram as the reference cardiac cycle, were prospectively studied. From the LA LS curve we measured the extent of the negative deflection (LSneg), representing LA active contraction, the positive deflection (LSpos) during LA filling, and total LS (LStot), as the sum of LSneg and LSpos values.
Average values for biplane LA LSpos, LSneg, and LStot were 19.7%, -14.5%, and 33.3%, respectively. On multivariate analysis, age, left ventricular (LV) global LS and volume, and LV diastolic function were the main physiologic determinants of LA LSpos (R
= 0.57) and LStot (R
= 0.40), whereas systolic blood pressure, E/A ratio, global LS, and LV stroke volume were the main determinants of LA LSneg (R
= 0.20). Women had higher LSpos and LStot than men, particularly before 50 years of age. LA LSpos and LStot decreased with aging, with different trends in men and women.
LA LS values are different in men and women and should be interpreted taking into account patient age and LV function as well. These reference values may help identify subclinical LA dysfunction in several cardiovascular or systemic conditions.
Three-Dimensional Electroanatomical Voltage Mapping and Histologic Evaluation of Myocardial Substrate in Right Ventricular Outflow Tract Tachycardia Domenico Corrado, Cristina Basso, Loira Leoni, ...Barbara Tokajuk, Pietro Turrini, Barbara Bauce, Federico Migliore, Andrea Pavei, Giuseppe Tarantini, Massimo Napodano, Angelo Ramondo, Gianfranco Buja, Sabino Iliceto, Gaetano Thiene Twenty-seven patients (15 men and 12 women, age 33.9 ± 8 years) with right ventricular outflow tract (RVOT) tachycardia and no right ventricular (RV) dilation/dysfunction were studied by electroanatomical voltage mapping (EVM) and endomyocardial biopsy (EMB) before catheter ablation. Right ventricular EVM was normal in 20 of 27 patients (74%, group A), whereas the other 7 patients (26%, group B) showed RVOT electroanatomical scars that correlated with fibrofatty myocardial replacement at EMB (p < 0.001). Three of 7 patients (43%) from group B received an implantable defibrillator during the follow-up, compared with no patients from group A (p = 0.012). Electroanatomical voltage mapping is able to identify RVOT tachycardia due to concealed arrhythmogenic RV cardiomyopathy/dysplasia.
Large thrombus burden (LTB) lesions in the context of primary percutaneous coronary intervention (p-PCI) have been related to unsuccessful angiographic reperfusion and unfavorable clinical outcomes. ...However, the hazard of LTB treatment on myocardial damage has not been evaluated. We investigated the impact of LTB on myocardial damage using contrast-enhanced cardiac magnetic resonance (CE-CMR) in the setting of p-PCI. In 327 patients, who underwent p-PCI without thrombus aspiration within 12 hours from symptom onset, we prospectively assessed the impact of LTB on infarct size and microvascular damage using CE-CMR. LTB was defined by the presence of Thrombolysis In Myocardial Infarction thrombus score ≥3 in patent infarct-related artery (IRA); or by “cut-off” occlusion pattern and/or large reference vessel diameter (≥3.5 mm) in occluded IRA. One hundred ninety-seven patients (60.2%) showed LTB and 130 (39.8%) did not. Distal embolization occurred in 18.8% patients with versus 6.9% without LTB (p = 0.003). At CE-CMR, patients with LTB had larger infarct size index (27.5 ± 11.1 vs 22.1 ± 17.5, p = 0.009) and more often transmural necrosis (70.5% vs 55.4%, p = 0.008) compared with patients without LTB. Excluding patients with distal embolization, patients with LTB still had larger necrosis. At multivariate analysis, occluded (IRA) at baseline, anterior infarction, and presence of LTB predicted transmural necrosis. In conclusion, LTB in the setting of p-PCI is related to larger myocardial damage as detected by CE-CMR, regardless of angiographic detectable distal embolization.
Despite growing interest in applying three-dimensional (3D) speckle-tracking echocardiography (STE) to measure left ventricular (LV) myocardial deformation in various diseases, normative values for ...3D speckle-tracking echocardiographic parameters and the effects of demographic, hemodynamic, and technical factors on these values are unknown.
In 265 healthy volunteers (age range, 18-76; 57% women), longitudinal strain (3DLε), circumferential strain (3DCε), radial strain (3DRε), and area strain (3DAε) were measured by using vendor-specific (Vsp) 3D speckle-tracking echocardiographic equipment. LV strain was also measured by using Vsp two-dimensional (2D) and vendor-independent 3D speckle-tracking echocardiographic software packages, for comparison.
Reference values (lower limit of normality) for Vsp 3D STE were -17% to -21% (-15%) for 3DLε, -17% to -20% (-14%) for 3DCε, -31% to -36% (-26%) for 3DAε, and 47% to 59% (38%) for 3DRε. Three-dimensional longitudinal strain decreased, whereas 3DCε increased, with aging (P < .003), with different trends in men and women. Men had lower 3DLε, 3DRε, 3DAε, and 2D longitudinal strain than women (P < .02). LV 3D strain parameters were also influenced by LV volumes and mass, image quality, and temporal resolution (P < .02). Reference values obtained by Vsp 2D STE were -20% to -23% (-18%) for 2D longitudinal strain, -20% to -24% (-17%) for 2D circumferential strain, and 39% to 54% (28%) for 2D radial strain (P < .001 vs Vsp 3D STE). Significantly different 3DCε and 3DRε values were obtained with vendor-independent versus Vsp 3D STE (P < .001).
In healthy subjects, reference values of LV 3D strain parameters were significantly influenced by demographic, cardiac, and technical factors. Limits of normality of LV strain by Vsp 3D STE should not be used interchangeably with Vsp 2D STE or with Vin 3D STE software.
Tako-Tsubo cardiomyopathy (TTC) presents with chest pain, ST-segment elevation followed by T-wave inversion and QT interval prolongation (Wellens' electrocardiographic ECG pattern), and left ...ventricular dysfunction, which may mimic an acute coronary syndrome.
To assess the pathophysiologic basis of the Wellens' ECG pattern in TTC by characterization of underlying myocardial changes by using cardiac magnetic resonance (CMR).
The study population included 20 consecutive patients with TTC (95% women; mean age 65.3 ± 10.4 years) who underwent CMR studies both in the initial phase and after 3-month follow-up by using a protocol that included cine images, T2-weighted sequences for myocardial edema, and post-contrast sequences for late gadolinium enhancement. Quantitative ECG indices of repolarization, such as maximal amplitude of negative T waves, sum of the amplitudes of negative T waves, and maximum corrected QT interval (QTc max), were correlated to CMR findings.
At the time of initial CMR study, there was a significant linear correlation between the apicobasal ratio of T2-weighted signal intensity for myocardial edema and the maximal amplitude of negative T waves (ρ = 0.498; P = .02), sum of the amplitudes of negative T waves (ρ = 0.483; P = .03), and maximum corrected QT interval (ρ = 0.520; P = .02). Repolarization indices were unrelated to either late gadolinium enhancement or quantitative cine parameters. Wellens' ECG abnormalities and myocardial edema showed a parallel time course of development and resolution on initial and follow-up CMR studies.
Our study results show that the ischemic-like Wellens' ECG pattern in TTC coincides and quantitatively correlates with the apicobasal gradient of myocardial edema as evidenced by using CMR. Dynamic negative T waves and QTc prolongation are likely to reflect the edema-induced transient inhomogeneity and dispersion of repolarization between apical and basal left ventricular regions.
Tricuspid annular (TA) size and function play important roles in planning the need for associated TA annuloplasty in patients undergoing cardiac surgery for left-sided heart valve diseases. However, ...TA diameter normative values and the extent of TA dynamic changes during cardiac cycle remain to be established.
This was a prospective, cross-sectional study of 219 healthy volunteers (mean age, 43 ± 15 years; 57% women), using conventional two-dimensional transthoracic echocardiographic (2DE) imaging to assess the variability of TA diameter measurement in relation to 2DE view and timing during cardiac cycle. TA diameter was obtained from apical right ventricular (RV)-focused four-chamber, parasternal long-axis RV inflow, and parasternal short-axis at aortic plane 2DE views at five time points during the cardiac cycle. Right atrial and RV volumes were measured using three-dimensional echocardiography.
TA diameters differed significantly among the three 2DE views and changed significantly during the cardiac cycle in all views. Moreover, mean fractional shortening of TA diameter was 24 ± 6% in the four-chamber view, 20 ± 7% in the parasternal long-axis RV inflow view, and 29 ± 11% in the parasternal short-axis at aortic plane view. One multivariate linear regression analysis, age, gender, and right atrial and RV volumes were independently correlated with TA diameters and accounted for 55% of the variance of midsystolic TA diameter in the four-chamber view.
This study provides references values for TA diameters and dynamics using 2DE imaging. Age, gender, and right chamber sizes, as well as the 2DE view and time during the cardiac cycle, significantly influenced TA diameters in healthy individuals. These data may help better identify TA dilatation using 2DE imaging for surgical planning.
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