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Utility of T-wave amplitude as a non-invasive risk marker of sudden cardiac death in hypertrophic cardiomyopathy

View Article: PubMed Central - PubMed

ABSTRACT

Objective: Sudden cardiac arrest (SCA) is the most devastating outcome in hypertrophic cardiomyopathy (HCM). We evaluated repolarisation features on the surface electrocardiogram (ECG) to identify the potential risk factors for SCA.

Methods: Data was collected from 52 patients with HCM who underwent implantable cardioverter defibrillator (ICD) implantation. Leads V2 and V5 from the ECG closest to the time of ICD implant were utilised for measuring the Tpeak-Tend interval (Tpe), QTc, Tpe/QTc, T-wave duration and T-wave amplitude. The presence of the five traditional SCA-associated risk factors was assessed, as well as the HCM risk-SCD score.

Results: 16 (30%) patients experienced aborted cardiac arrest over 8.5±4.1 years, with 9 receiving an ICD shock and 7 receiving ATP. On univariate analysis, T-wave amplitude was associated with appropriate ICD therapy (HR per 0.1 mV 0.79, 95% CI 0.56 to 0.96, p=0.02). Aborted SCA was not associated with a greater mean QTc duration, Tpeak-Tend interval, T-wave duration, or Tpe/QT ratio. Multivariate analysis (adjusting for cardinal HCM SCA-risk factors) showed T-wave amplitude in Lead V2 was an independent predictor of risk (adjusted HR per 0.1 mV 0.74, 95% CI 0.57 to 0.97, p=0.03). Addition of T-wave amplitude in Lead V2 to the traditional risk factors resulted in significant improvement in risk stratification (C-statistic from 0.65 to 0.75) but did not improve the performance of the HCM SCD-risk score.

Conclusions: T-wave amplitude is a novel marker of SCA in this high risk HCM population and may provide incremental predictive value to established risk factors. Further work is needed to define the role of repolarisation abnormalities in predicting SCA in HCM.

No MeSH data available.


Related in: MedlinePlus

Average ECG tracings of the HCM cohort, separated by appropriate ICD therapy. HCM, hypertrophic cardiomyopathy; ICD, implantable cardioverter defibrillator.
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OPENHRT2016000561F2: Average ECG tracings of the HCM cohort, separated by appropriate ICD therapy. HCM, hypertrophic cardiomyopathy; ICD, implantable cardioverter defibrillator.

Mentions: ECG variables (lead V2 and V5) are summarised in table 3. Figure 2 highlights the average T-wave from all the patients with HCM included and separated by aborted SCA event occurrence. T-wave amplitude was reduced in individuals who experienced an aborted SCA event during follow-up (figure 2). Specifically, in lead V2, T-wave amplitude was 0.34±0.18 mV in those that experienced aborted SCA vs 0.55±0.3 mV in those who did not. In lead V5 a similar pattern was observed with reduced T-wave amplitude in those that experienced an abort SCA event, 0.20±0.14 vs 0.29±0.27 mV. In lead V2 the average QTc of those that experienced events was 427±29 vs 418±35 ms and in lead V5 446±34 vs 432±43 ms.


Utility of T-wave amplitude as a non-invasive risk marker of sudden cardiac death in hypertrophic cardiomyopathy
Average ECG tracings of the HCM cohort, separated by appropriate ICD therapy. HCM, hypertrophic cardiomyopathy; ICD, implantable cardioverter defibrillator.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC5384475&req=5

OPENHRT2016000561F2: Average ECG tracings of the HCM cohort, separated by appropriate ICD therapy. HCM, hypertrophic cardiomyopathy; ICD, implantable cardioverter defibrillator.
Mentions: ECG variables (lead V2 and V5) are summarised in table 3. Figure 2 highlights the average T-wave from all the patients with HCM included and separated by aborted SCA event occurrence. T-wave amplitude was reduced in individuals who experienced an aborted SCA event during follow-up (figure 2). Specifically, in lead V2, T-wave amplitude was 0.34±0.18 mV in those that experienced aborted SCA vs 0.55±0.3 mV in those who did not. In lead V5 a similar pattern was observed with reduced T-wave amplitude in those that experienced an abort SCA event, 0.20±0.14 vs 0.29±0.27 mV. In lead V2 the average QTc of those that experienced events was 427±29 vs 418±35 ms and in lead V5 446±34 vs 432±43 ms.

View Article: PubMed Central - PubMed

ABSTRACT

Objective: Sudden cardiac arrest (SCA) is the most devastating outcome in hypertrophic cardiomyopathy (HCM). We evaluated repolarisation features on the surface electrocardiogram (ECG) to identify the potential risk factors for SCA.

Methods: Data was collected from 52 patients with HCM who underwent implantable cardioverter defibrillator (ICD) implantation. Leads V2 and V5 from the ECG closest to the time of ICD implant were utilised for measuring the Tpeak-Tend interval (Tpe), QTc, Tpe/QTc, T-wave duration and T-wave amplitude. The presence of the five traditional SCA-associated risk factors was assessed, as well as the HCM risk-SCD score.

Results: 16 (30%) patients experienced aborted cardiac arrest over 8.5±4.1 years, with 9 receiving an ICD shock and 7 receiving ATP. On univariate analysis, T-wave amplitude was associated with appropriate ICD therapy (HR per 0.1 mV 0.79, 95% CI 0.56 to 0.96, p=0.02). Aborted SCA was not associated with a greater mean QTc duration, Tpeak-Tend interval, T-wave duration, or Tpe/QT ratio. Multivariate analysis (adjusting for cardinal HCM SCA-risk factors) showed T-wave amplitude in Lead V2 was an independent predictor of risk (adjusted HR per 0.1 mV 0.74, 95% CI 0.57 to 0.97, p=0.03). Addition of T-wave amplitude in Lead V2 to the traditional risk factors resulted in significant improvement in risk stratification (C-statistic from 0.65 to 0.75) but did not improve the performance of the HCM SCD-risk score.

Conclusions: T-wave amplitude is a novel marker of SCA in this high risk HCM population and may provide incremental predictive value to established risk factors. Further work is needed to define the role of repolarisation abnormalities in predicting SCA in HCM.

No MeSH data available.


Related in: MedlinePlus