Microvolt QRS Alternans Without Microvolt T‐Wave Alternans in Human Cardiomyopathy: A Novel Risk Marker of Late Ventricular Arrhythmias
Background Action potential alternans can induce ventricular tachyarrhythmias and manifest on the surface ECG as T‐wave alternans (TWA) and QRS alternans (QRSA). We sought to evaluate microvolt QRSA in cardiomyopathy patients in relation to TWA and ventricular tachyarrhythmia outcomes. Methods and R...
| Main Authors: | , , , , , , |
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| Format: | Article |
| Language: | English |
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Wiley
2020-09-01
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| Series: | Journal of the American Heart Association: Cardiovascular and Cerebrovascular Disease |
| Subjects: | |
| Online Access: | https://www.ahajournals.org/doi/10.1161/JAHA.119.016461 |
| _version_ | 1818775936386990080 |
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| author | Adrian Suszko Sachin Nayyar Christopher Labos Kumaraswamy Nanthakumar Arnold Pinter Eugene Crystal Vijay S. Chauhan |
| author_facet | Adrian Suszko Sachin Nayyar Christopher Labos Kumaraswamy Nanthakumar Arnold Pinter Eugene Crystal Vijay S. Chauhan |
| author_sort | Adrian Suszko |
| collection | DOAJ |
| description | Background Action potential alternans can induce ventricular tachyarrhythmias and manifest on the surface ECG as T‐wave alternans (TWA) and QRS alternans (QRSA). We sought to evaluate microvolt QRSA in cardiomyopathy patients in relation to TWA and ventricular tachyarrhythmia outcomes. Methods and Results Prospectively enrolled cardiomyopathy patients (n=100) with prophylactic defibrillators had 12‐lead ECGs recorded during ventricular pacing from 100 to 120 beats/min. QRSA and TWA were quantified in moving 128‐beat segments using the spectral method. Segments were categorized as QRSA positive (QRSA+) and/or TWA positive (TWA+) based on ≥2 precordial leads having alternans magnitude >0 and signal:noise >3. Patients were similarly categorized based on having ≥3 consecutive segments with alternans. TWA+ and QRSA+ occurred together in 31% of patients and alone in 18% and 14% of patients, respectively. Although TWA magnitude (1.4±0.4 versus 4.7±1.0 µV, P<0.01) and proportion of TWA+ studies (16% versus 46%, P<0.01) increased with rate, QRSA did not change. QRS duration was longer in QRSA+ than QRSA‐negative patients (138±23 versus 113±26 ms, P<0.01). At 3.5 years follow‐up, appropriate defibrillator therapy or sustained ventricular tachyarrhythmia was greater in QRSA+ than QRSA‐negative patients (30% versus 8%, P=0.02) but similar in TWA+ and TWA‐negative patients. Among QRSA+ patients, the event rate was greater in those without TWA (62% versus 21%, P=0.02). Multivariable Cox analysis revealed QRSA+ (hazard ratio [HR], 4.6; 95% CI, 1.5–14; P=0.009) and QRS duration >120 ms (HR, 4.1; 95% CI, 1.3–12; P=0.014) to predict events. Conclusions Microvolt QRSA is novel phenomenon in cardiomyopathy patients that can exist without TWA and is associated with QRS prolongation. QRSA increases the risk of ventricular tachyarrhythmia 4‐fold, which merits further study as a risk stratifier. |
| first_indexed | 2024-12-18T11:04:57Z |
| format | Article |
| id | doaj.art-6a4aadf3a7114ab1982bf6b6262419fc |
| institution | Directory Open Access Journal |
| issn | 2047-9980 |
| language | English |
| last_indexed | 2024-12-18T11:04:57Z |
| publishDate | 2020-09-01 |
| publisher | Wiley |
| record_format | Article |
| series | Journal of the American Heart Association: Cardiovascular and Cerebrovascular Disease |
| spelling | doaj.art-6a4aadf3a7114ab1982bf6b6262419fc2022-12-21T21:10:09ZengWileyJournal of the American Heart Association: Cardiovascular and Cerebrovascular Disease2047-99802020-09-0191710.1161/JAHA.119.016461Microvolt QRS Alternans Without Microvolt T‐Wave Alternans in Human Cardiomyopathy: A Novel Risk Marker of Late Ventricular ArrhythmiasAdrian Suszko0Sachin Nayyar1Christopher Labos2Kumaraswamy Nanthakumar3Arnold Pinter4Eugene Crystal5Vijay S. Chauhan6Peter Munk Cardiac Center University Health Network Toronto Ontario CanadaPeter Munk Cardiac Center University Health Network Toronto Ontario CanadaQueen Elizabeth Health Complex Montreal Quebec CanadaPeter Munk Cardiac Center University Health Network Toronto Ontario CanadaDivision of Cardiology St. Michael’s Hospital Toronto Ontario CanadaDivision of Cardiology Sunnybrook Health Sciences Center Toronto Ontario CanadaPeter Munk Cardiac Center University Health Network Toronto Ontario CanadaBackground Action potential alternans can induce ventricular tachyarrhythmias and manifest on the surface ECG as T‐wave alternans (TWA) and QRS alternans (QRSA). We sought to evaluate microvolt QRSA in cardiomyopathy patients in relation to TWA and ventricular tachyarrhythmia outcomes. Methods and Results Prospectively enrolled cardiomyopathy patients (n=100) with prophylactic defibrillators had 12‐lead ECGs recorded during ventricular pacing from 100 to 120 beats/min. QRSA and TWA were quantified in moving 128‐beat segments using the spectral method. Segments were categorized as QRSA positive (QRSA+) and/or TWA positive (TWA+) based on ≥2 precordial leads having alternans magnitude >0 and signal:noise >3. Patients were similarly categorized based on having ≥3 consecutive segments with alternans. TWA+ and QRSA+ occurred together in 31% of patients and alone in 18% and 14% of patients, respectively. Although TWA magnitude (1.4±0.4 versus 4.7±1.0 µV, P<0.01) and proportion of TWA+ studies (16% versus 46%, P<0.01) increased with rate, QRSA did not change. QRS duration was longer in QRSA+ than QRSA‐negative patients (138±23 versus 113±26 ms, P<0.01). At 3.5 years follow‐up, appropriate defibrillator therapy or sustained ventricular tachyarrhythmia was greater in QRSA+ than QRSA‐negative patients (30% versus 8%, P=0.02) but similar in TWA+ and TWA‐negative patients. Among QRSA+ patients, the event rate was greater in those without TWA (62% versus 21%, P=0.02). Multivariable Cox analysis revealed QRSA+ (hazard ratio [HR], 4.6; 95% CI, 1.5–14; P=0.009) and QRS duration >120 ms (HR, 4.1; 95% CI, 1.3–12; P=0.014) to predict events. Conclusions Microvolt QRSA is novel phenomenon in cardiomyopathy patients that can exist without TWA and is associated with QRS prolongation. QRSA increases the risk of ventricular tachyarrhythmia 4‐fold, which merits further study as a risk stratifier.https://www.ahajournals.org/doi/10.1161/JAHA.119.016461cardiomyopathyECGQRS alternansT‐wave alternansventricular arrhythmia |
| spellingShingle | Adrian Suszko Sachin Nayyar Christopher Labos Kumaraswamy Nanthakumar Arnold Pinter Eugene Crystal Vijay S. Chauhan Microvolt QRS Alternans Without Microvolt T‐Wave Alternans in Human Cardiomyopathy: A Novel Risk Marker of Late Ventricular Arrhythmias Journal of the American Heart Association: Cardiovascular and Cerebrovascular Disease cardiomyopathy ECG QRS alternans T‐wave alternans ventricular arrhythmia |
| title | Microvolt QRS Alternans Without Microvolt T‐Wave Alternans in Human Cardiomyopathy: A Novel Risk Marker of Late Ventricular Arrhythmias |
| title_full | Microvolt QRS Alternans Without Microvolt T‐Wave Alternans in Human Cardiomyopathy: A Novel Risk Marker of Late Ventricular Arrhythmias |
| title_fullStr | Microvolt QRS Alternans Without Microvolt T‐Wave Alternans in Human Cardiomyopathy: A Novel Risk Marker of Late Ventricular Arrhythmias |
| title_full_unstemmed | Microvolt QRS Alternans Without Microvolt T‐Wave Alternans in Human Cardiomyopathy: A Novel Risk Marker of Late Ventricular Arrhythmias |
| title_short | Microvolt QRS Alternans Without Microvolt T‐Wave Alternans in Human Cardiomyopathy: A Novel Risk Marker of Late Ventricular Arrhythmias |
| title_sort | microvolt qrs alternans without microvolt t wave alternans in human cardiomyopathy a novel risk marker of late ventricular arrhythmias |
| topic | cardiomyopathy ECG QRS alternans T‐wave alternans ventricular arrhythmia |
| url | https://www.ahajournals.org/doi/10.1161/JAHA.119.016461 |
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