Microvolt QRS Alternans in Hypertrophic Cardiomyopathy: A Novel Risk Marker of Late Ventricular Arrhythmias
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 Prospe...
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Format: | Article |
Language: | English |
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Wiley
2021-12-01
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Series: | Journal of the American Heart Association: Cardiovascular and Cerebrovascular Disease |
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Online Access: | https://www.ahajournals.org/doi/10.1161/JAHA.121.022036 |
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author | Praloy Chakraborty Adrian M. Suszko Karthik Viswanathan Kimia Sheikholeslami Danna Spears Arnon Adler Anna Woo Harry Rakowski Vijay S. Chauhan |
author_facet | Praloy Chakraborty Adrian M. Suszko Karthik Viswanathan Kimia Sheikholeslami Danna Spears Arnon Adler Anna Woo Harry Rakowski Vijay S. Chauhan |
author_sort | Praloy Chakraborty |
collection | DOAJ |
description | 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. |
first_indexed | 2024-04-10T20:12:09Z |
format | Article |
id | doaj.art-367c94e1476549b583486bd4b42a5c58 |
institution | Directory Open Access Journal |
issn | 2047-9980 |
language | English |
last_indexed | 2024-04-10T20:12:09Z |
publishDate | 2021-12-01 |
publisher | Wiley |
record_format | Article |
series | Journal of the American Heart Association: Cardiovascular and Cerebrovascular Disease |
spelling | doaj.art-367c94e1476549b583486bd4b42a5c582023-01-26T10:36:40ZengWileyJournal of the American Heart Association: Cardiovascular and Cerebrovascular Disease2047-99802021-12-01102310.1161/JAHA.121.022036Microvolt QRS Alternans in Hypertrophic Cardiomyopathy: A Novel Risk Marker of Late Ventricular ArrhythmiasPraloy Chakraborty0Adrian M. Suszko1Karthik Viswanathan2Kimia Sheikholeslami3Danna Spears4Arnon Adler5Anna Woo6Harry Rakowski7Vijay S. Chauhan8Division of Cardiology Peter Munk Cardiac Center University Health Network Toronto Ontario CanadaDivision of Cardiology Peter Munk Cardiac Center University Health Network Toronto Ontario CanadaDivision of Cardiology Peter Munk Cardiac Center University Health Network Toronto Ontario CanadaDivision of Cardiology Peter Munk Cardiac Center University Health Network Toronto Ontario CanadaDivision of Cardiology Peter Munk Cardiac Center University Health Network Toronto Ontario CanadaDivision of Cardiology Peter Munk Cardiac Center University Health Network Toronto Ontario CanadaDivision of Cardiology Peter Munk Cardiac Center University Health Network Toronto Ontario CanadaDivision of Cardiology Peter Munk Cardiac Center University Health Network Toronto Ontario CanadaDivision of Cardiology Peter Munk Cardiac Center University Health Network Toronto Ontario CanadaBackground 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.https://www.ahajournals.org/doi/10.1161/JAHA.121.022036alternansECGhypertrophic cardiomyopathyrisk assessmentventricular arrhythmia |
spellingShingle | Praloy Chakraborty Adrian M. Suszko Karthik Viswanathan Kimia Sheikholeslami Danna Spears Arnon Adler Anna Woo Harry Rakowski Vijay S. Chauhan Microvolt QRS Alternans in Hypertrophic Cardiomyopathy: A Novel Risk Marker of Late Ventricular Arrhythmias Journal of the American Heart Association: Cardiovascular and Cerebrovascular Disease alternans ECG hypertrophic cardiomyopathy risk assessment ventricular arrhythmia |
title | Microvolt QRS Alternans in Hypertrophic Cardiomyopathy: A Novel Risk Marker of Late Ventricular Arrhythmias |
title_full | Microvolt QRS Alternans in Hypertrophic Cardiomyopathy: A Novel Risk Marker of Late Ventricular Arrhythmias |
title_fullStr | Microvolt QRS Alternans in Hypertrophic Cardiomyopathy: A Novel Risk Marker of Late Ventricular Arrhythmias |
title_full_unstemmed | Microvolt QRS Alternans in Hypertrophic Cardiomyopathy: A Novel Risk Marker of Late Ventricular Arrhythmias |
title_short | Microvolt QRS Alternans in Hypertrophic Cardiomyopathy: A Novel Risk Marker of Late Ventricular Arrhythmias |
title_sort | microvolt qrs alternans in hypertrophic cardiomyopathy a novel risk marker of late ventricular arrhythmias |
topic | alternans ECG hypertrophic cardiomyopathy risk assessment ventricular arrhythmia |
url | https://www.ahajournals.org/doi/10.1161/JAHA.121.022036 |
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