New ECG Criteria May Allow Early Detection of Hypertension-Mediated Organ Damage – The Cardiology Advisor

Electrocardiography (ECG) is a valuable tool to assess left ventricular hypertrophy (LVH), which has been associated with the development of major cardiovascular events. A set of new ECG criteria, with higher sensitivity than conventional criteria, may allow the early identification of hypertension-mediated organ damage, according to a narrative review published in the Journal of Clinical Hypertension.1

Essential hypertension is a significant risk factor for cardiovascular morbidity and mortality, and previous studies have reported increased risk for myocardial infarction, stroke, and congestive heart failure in patients with hypertension. Although diagnosing hypertension early may help mitigate cardiovascular risks, studies indicate that lowering blood pressure to the target range may not be sufficient to reduce these risks.

One of the most important markers of hypertension-mediated organ damage is left ventricular hypertrophy (LVH), which is characterized by increased left ventricle (LV) mass and remodeling as a result of elevated blood pressure. Hypertension-mediated organ damage is associated with increased risks for arrhythmias, coronary artery disease, myocardial infarction, and congestive heart failure.

Persistent hypertension may lead to concentric LV remodeling, characterized by increased LV wall thickness with normal LV mass. In later stages, LVH is associated with diastolic dysfunction, abnormal LV relaxation, LV enlargement, and systolic dysfunction. Hypertensive heart disease includes conditions ranging from asymptomatic LVH to heart failure with preserved, midrange, or reduced ejection fraction.

Echocardiography has long been considered the gold standard to detect LVH. However, because of related costs, the technique is not adequate for routine use in clinical practice as a screening test for all patients with hypertension.

Although 12-lead conventional ECG is highly specific and commonly used to detect LVH, the technique has relatively low sensitivity, especially in obese patients.

Most ECG criteria, including the Sokolow-Lyon, Gubner-Underleider, Lewis, Cornell, and Framingham criteria, for detection of LVH are based on QRS voltage criteria. These criteria have been found to have relatively high specificity and low sensitivity, rendering them inadequate to rule out LVH in hypertensive patients.

Novel ECG criteria were found to be more sensitive and to improve the LVH diagnostic accuracy of ECG. These newer criteria include the Perugia criterion, time interval between the peak and the end of the T wave (Tp-Te), and ventricular activation time (VAT).

In a study in which the accuracy and prognostic values of a set of ECG criteria were evaluated in patients with hypertension, Perugia score (hazard ratio [HR], 2.04; 95% CI, 1.5-2.8) and Framingham (HR, 1.91; 95% CI, 1.1-3.2), Romhilt-Estes (HR, 2.63; 95% CI, 1.7-4.1), and strain (HR, 2.11; 95% CI, 1.4-3.2) methods were found to be associated with an increased cardiovascular risk.2 The Perugia score had the highest population-attributable cardiovascular risk compared with the other criteria tested, and LVH diagnosed using this criterion was associated with an increased risk for cardiovascular mortality (HR, 4.21; 95% CI, 2.1-8.7).

The Tp-Te interval was found to be related to increased LV mass and high 24-hour ambulatory blood pressure levels. This interval was longer in hypertensive vs normotensive patients. Abnormal Tp-Te interval was found to be more common in patients with vs without coronary artery disease, and when adjusted for heart rate, the Tp-Te interval was found to be associated with increased cardiovascular risk. This criterion may be a predictor of ventricular arrhythmias and mortality in patients with long QT or Brugada syndrome, as well as in patients treated with primary coronary intervention within 1 year of an ischemic event.

A potential marker of diastolic dysfunction is VAT, defined as the time interval between the beginning of the QRS complex and the peak of the R wave. An association was established between an increase in VAT and an increase in atrial and septum diameters, LV mass index, and low e velocity.3

We talked with Ran Kornowski, MD, FACC, FESC, director of the Cardiology Division at Rabin Medical Center, Petach Tikva, Israel, who was not involved in the study. The subject is clinically important, since hypertension-mediated left ventricular hypertrophy is frequently observed in hypertensive patients, and it has a profound deleterious cardiovascular prognostic impact, he noted.

Since the most common first-line method to evaluate LVH is the 12-lead conventional ECG, due to its widespread availability, it is crucial to acknowledge the often-forgotten main conventional and novel 12-lead ECG criteria for the assessment of LVH in order to improve the diagnostic work-up in hypertensive patients. Overall, the 12-lead ECG has a low sensitivity but high specificity for detecting LVH. There are few large-scale studies in which the 12-lead ECG morphology vs cardiac echocardiography have been compared, or in which the ECG response to pharmacotherapy and/or lifestyle interventions have been examined. I think that this is a topic wherein data mining and artificial intelligence could play a role, and more research geared toward these types of diagnostic tools might be useful.

Dr Kornowski added: The authors of the narrative review nicely describe the methods in clinical use for detecting 12-lead ECG-based LVH, ranging from the classic Sokolow-Lyon voltage description up to the more contemporary Perugia score, as well as other methods. The external validity of those criteria and the ability to implement the various criteria in heterogeneous populations of hypertensive patients in different areas the world are still up for debate.

The narrative review authors concluded: On the basis of the currently available evidence, several new ECG criteria can be proposed for being applied in routine practice, among which the assessment of Tp-Te interval can be considered one of the most promising tools for early identification of electrophysiology risk in hypertensive patients with LVH.

References

1. Miceli F, Presta V, Citoni B, et al. Conventional and new electrocardiographic criteria for hypertension-mediated cardiac organ damage: A narrative review. J Clin Hypertens (Greenwich). 2019;21(12):1863-1871. doi:10.1111/jch.13726

2. Verdecchia P, Schillaci G, Borgioni C, et al. Prognostic value of a new electrocardiographic method for diagnosis of left ventricular hypertrophy in essential hypertension. J Am Coll Cardiol. 1998;31:383390.

3. Boles U, Almuntaser I, Brown A, Murphy RR, Mahmud A, Feely J. Ventricular activation time as a marker for diastolic dysfunction in early hypertension. Am J Hypertens. 2010;23:781785.

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New ECG Criteria May Allow Early Detection of Hypertension-Mediated Organ Damage - The Cardiology Advisor