Late gadolinium enhancement of cardiac magnetic resonance imaging indicates abnormalities of time-domain T-wave alternans in hypertrophic cardiomyopathy with ventricular tachycardia

Naka, Sadahiro; Sato, Nobuyuki; Oikawa, Kensuke; Talib, Ahmed Karim; Sugiyama, Eitaro; Minoshima, Akiho; Tanabe, Yasuko; Takeuchi, Toshiharu; Akasaka, Keiichi; Saijo, Yasuaki; Kawamura, Y.; Hasebe, Naoyuki

doi:10.1016/j.hrthm.2015.04.028

Cited by 8 publications

(2 citation statements)

References 34 publications

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“… 23 For HCM, the pathogenesis of electrical alternans has not been well defined, but TWA magnitude appears to correlate with the extent of myocyte disarray and interstitial fibrosis on histology 7 , 24 as well as CMR LGE. 25 Our patients with TWA were also found to have greater LV wall thickness compared with those without TWA, which is consistent with Puntmann et al 8 Although abnormal intracellular calcium cycling may cause TWA with or without QRSA in HCM, this does not explain why 7% of our patients had isolated QRSA. An alternative mechanism may invoke myocardial conduction alternans, whereby propagation into the abnormal myoarchitecture alternates between 2 distinct conducting pathways leading to beat‐to‐beat alterations in ventricular activation.…”

Section: Discussionsupporting

confidence: 90%

“… 16 , 17 In HCM, the prevalence and magnitude of TWA are greater in high versus low‐risk patients. 6 , 7 , 25 However, there are conflicting reports regarding the prognostic utility of TWA for future VA events. 8 , 9 In our larger, high‐risk HCM cohort, TWA did not predict VA over a 5‐year follow‐up period using either the traditional TWA definition of V alt >1.9 µV or V alt >0.…”

Section: Discussionmentioning

confidence: 99%

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Microvolt QRS Alternans in Hypertrophic Cardiomyopathy: A Novel Risk Marker of Late Ventricular Arrhythmias

Chakraborty

Suszko

Viswanathan

et al. 2021

JAHA

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Background Unlike T‐wave alternans (TWA), the relation between QRS alternans (QRSA) and ventricular arrhythmia (VA) risk has not been evaluated in hypertrophic cardiomyopathy (HCM). We assessed microvolt QRSA/TWA in relation to HCM risk factors and late VA outcomes in HCM. Methods and Results Prospectively enrolled patients with HCM (n=130) with prophylactic implantable cardioverter‐defibrillators underwent digital 12‐lead ECG recordings during ventricular pacing (100–120 beats/min). QRSA/TWA was quantified using the spectral method. Patients were categorized as QRSA+ and/or TWA+ if sustained alternans was present in ≥2 precordial leads. The VA end point was appropriate implantable cardioverter‐defibrillator therapy over 5 years of follow‐up. QRSA+ and TWA+ occurred together in 28% of patients and alone in 7% and 7% of patients, respectively. QRSA magnitude increased with pacing rate (1.9±0.6 versus 6.2±2.0 µV; P =0.006). Left ventricular thickness was greater in QRSA+ than in QRSA− patients (22±7 versus 20±6 mm; P =0.035). Over 5 years follow‐up, 17% of patients had VA. The annual VA rate was greater in QRSA+ versus QRSA− patients (5.8% versus 2.0%; P =0.006), with the QRSA+/TWA− subgroup having the greatest rate (13.3% versus 2.6%; P <0.001). In those with <2 risk factors, QRSA− patients had a low annual VA rate compared QRSA+ patients (0.58% versus 7.1%; P =0.001). Separate Cox models revealed QRSA+ (hazard ratio [HR], 2.9 [95% CI, 1.2–7.0]; P =0.019) and QRSA+/TWA− (HR, 7.9 [95% CI, 2.9–21.7]; P <0.001) as the most significant VA predictors. TWA and HCM risk factors did not predict VA. Conclusions In HCM, microvolt QRSA is a novel, rate‐dependent phenomenon that can exist without TWA and is associated with greater left ventricular thickness. QRSA increases VA risk 3‐fold in all patients, whereas the absence of QRSA confers low VA risk in patients with <2 risk factors. Registration URL: https://www.clinicaltrials.gov ; Unique identifier: NCT02560844.

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