Yonsei Med J.  2012 Jan;53(1):221-223. 10.3349/ymj.2012.53.1.221.

Mid-Septal Hypertrophy and Apical Ballooning; Potential Mechanism of Ventricular Tachycardia Storm in Patients with Hypertrophic Cardiomyopathy

• Hwang ES
• Pak HN

• KMID: 1779710
• DOI: http://doi.org/10.3349/ymj.2012.53.1.221

Abstract

Medically refractory ventricular tachycardia (VT) storm can be controlled with radiofrequency catheter ablation (RFCA), however, it may be difficult to control in some patients with hemodynamic overload. We experienced a patient with intractable VT storm controlled by hemodynamic unloading. The patient had mid-septal hypertrophic cardiomyopathy with an implantable cardioverter defibrillator (ICD) back-up. Because of the severe mid-septal hypertrophy, his left ventricle (LV) had an hourglass-like morphology and showed apical ballooning; the focus of VT was at the border of apical ballooning. Although we performed VT ablation because of electrical storm with multiple ICD shocks, VT recurred 1 hour after procedure. As the post-RFCA monomorphic VT was refractory to anti-tachycardia pacing or ICD shock, we reduced the hemodynamic overload of LV with beta-blockade, hydration, and sedation. VT spontaneously stopped 1.5 hours later and the patient has remained free of VT for 24 months with beta-blockade alone. In patients with VT storm refractory to antiarrhythmic drugs or RFCA, the mechanism of mechano-electrical feedback should be considered and hemodynamic unloading may be an essential component of treatment.

Keyword

Catheter ablation; radiofrequency; electrical storm; ventricular tachycardia; hypertrophic cardiomyopathy

MeSH Terms

Cardiomyopathy, Hypertrophic/complications/diagnosis/*physiopathology/therapy
Catheter Ablation
Electrocardiography
Gated Blood-Pool Imaging
Heart Catheterization
Humans
Male
Middle Aged
Tachycardia, Ventricular/diagnosis/etiology/*physiopathology/therapy
Takotsubo Cardiomyopathy/complications/diagnosis/*physiopathology/therapy

Figure

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  Fig. 1 (A and B) Cardiac CT images of left ventricle (LV) during systole and diastole. (C and D) 3D reconstructed CT images show LV cavity obstruction during systole because of significant mid-septal hypertrophy. (E) 12-lead ECG during ventricular tachycardia (VT) on admission, suggesting LV apical posterior wall origin of VT. CT, computed tomography.

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  Fig. 2 (A and B) Left ventriculograms of LAO 35° (B) and RAO 35° views. Due to severe mid-septal hypertrophy, the LV had an hourglass-like morphology showing apical ballooning. (C and D) Catheter positions of ablation site (marked with asterisk) in LAO 35° (C) and RAO 35° views (D) match to the margin of apical ballooning due to significant mid-septal hypertrophy. (E) Electroanatomical activation map revealed that the earliest activation site of VT was located at the apical posteroseptum of the LV at the border of apical ballooning. LAO, left anterior oblique view; RAO, right anterior oblique view; VT, ventricular tachycardia.

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  Fig. 3 During VT, the target ablation site (ABLd) preceded the QRS onset by 50 ms (vertical line). showing double potential. VT was terminated by mechanical bump or RF energy delivery. VT, ventricular tachycardia.

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