Elsevier

Heart Rhythm

Volume 10, Issue 5, May 2013, Pages 621-626
Heart Rhythm

Apical ventricular tachycardia morphology in left ventricular nonischemic cardiomyopathy predicts poor transplant-free survival

https://doi.org/10.1016/j.hrthm.2012.12.029Get rights and content

Background

The scar of patients with left ventricular (LV) nonischemic cardiomyopathy (NICM) and ventricular tachycardia (VT) typically originates at or near the mitral annulus and extends a variable distance toward the apex.

Objective

To determine whether electrocardiograms of VT with LV apical exit sites would identify patients with larger scars extending a greater distance from the base toward the apex and decreased heart transplant/left ventricular assist device (LVAD)-free survival.

Methods

Consecutive patients with LV NICM undergoing VT ablation between May 2008 and April 2011 were studied. All electrocardiograms of spontaneous and induced VT were analyzed. Apical VT was defined as left bundle branch morphology with precordial transition≥V5 or right bundle branch morphology with precordial transition≤V3. Scar percentage was defined as the area of low voltage divided by the total surface area.

Results

Thirty-two of 76 patients had 1 or more apical VTs. Those with apical VTs had larger percentage of endocardial and epicardial bipolar scars (14.9% vs 8.1%, P = .01, and 15.5% vs 5.5%, P = .03, respectively), scar that, although originating from the periannular region (94.7% of the patients), was more likely to extend apically beyond the basal half (48.3% vs 24.4%, P = .05 endocardial, and 85.7% vs 25.9%, P = .07 epicardial), and worse transplant/LVAD-free survival during a mean follow-up of 332 days (P = .006).

Conclusions

Patients with NICM and apical VTs have larger voltage abnormality extending as contiguous or patchy “scar” from the base further toward the apex and worse transplant/LVAD-free survival. Particular attention should be paid to optimal heart failure management in these patients, with more guarded prognosis.

Introduction

The area of low-voltage, abnormal bipolar electrograms consistent with “scar” in patients with left ventricular nonischemic cardiomyopathy (NICM) and ventricular tachycardia (VT) typically originates at or near the mitral annular region and extends a variable distance toward the apex.1 While patients with VT and NICM as a whole have better survival than those with VT and ischemic cardiomyopathy,2 there remains substantial variability in survival among those with NICM. We hypothesized that patients with NICM and VT morphologies suggesting an apical left ventricular exit site would have larger scars extending a greater distance from the base toward the apex and, consequently, worse transplant- and left ventricular assist device (LVAD)-free survival following ablation.

Section snippets

Study population

We studied consecutive patients with left ventricular NICM and sustained VT, who were referred to the Hospital of the University of Pennsylvania for ablation between May 2008 and April 2011. Patients with idiopathic VT, right ventricular cardiomyopathy, or ischemic cardiomyopathy, as defined by history of myocardial infarction or obstructive coronary artery disease on angiography, were excluded. Patients undergoing multiple ablation procedures during this time period were included once, with

Baseline, VT, and voltage map characteristics

Of 76 patients with NICM undergoing VT ablation, 16 had apical VT documented on spontaneous 12-lead ECG and an additional 16 had apical VT induced during electrophysiology study for a total of 32 patients (42%; Table 1). A mean of 371 points were recorded per endocardial voltage map and 554 points per epicardial map. Epicardial mapping was performed in 51% of patients. Compared to those without apical VTs, those with apical VTs had lower LVEF (23.1% vs 35.7%; P = .001), wider native QRS

Discussion

In a consecutive series of 76 patients with nonischemic left ventricular cardiomyopathy undergoing VT ablation, we found that patients with apical VT morphologies had larger areas of scar extending further from the base toward the apex, as defined by endocardial and epicardial voltage mapping. Patients with apical VTs were also more likely to die or require heart transplant or LVAD for end-stage heart failure. Despite a mean follow-up of less than 1 year, more than one-quarter of the patients

Conclusions

Patients with NICM and apical VTs have larger areas of scar extending further from the base toward the apex and worse transplant/LVAD-free survival, despite similar LVEF. Particular attention should be paid to optimal heart failure management in these patients, with a more guarded prognosis.

References (10)

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Cited by (26)

  • Ablation of Ventricular Arrhythmias From the Left Ventricular Apex in Patients Without Ischemic Heart Disease

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    Citation Excerpt :

    Regarding NICM, it has previously been reported that the substrate for VA is most commonly located at the basal periannular regions of the LV (14). Larger scars that extend from the periannular LV toward the apex have been associated with apical morphology VTs and worse transplant/LV assist device–free survival (15). Septal substrate, which may be intramural, is also well described in NICM and can be associated with multiple VA morphologies (16).

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This study was supported in part by the F. Harlan Batrus Research Fund and the Susan and Murray Bloom Fund.

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