Case #20 — Tall R Waves in Precordial Electrocardiogram Leads

by Maygen del Castillo, MD, Ihab Hamzeh, MD, FACC, and Yochai Birnbaum, MD, FACC

A 55-year-old man with a history of coronary artery bypass grafting and severe biventricular failure presented with several weeks of shortness of breath and associated chest pain. He needed an Impella® heart pump (Abiomed, Inc.) as mechanical circulatory support for volume overload and cardiogenic shock. His mildly elevated cardiac troponin I level (1.35 ng/mL on admission) was attributed to demand ischemia from decompensated heart failure; the level decreased after diuresis. He was referred for advanced heart failure evaluation. Figure 1 shows his electrocardiogram (ECG) on presentation.

Fig. 1

The ECG shows sinus rhythm with a premature atrial contraction, a premature ventricular contraction, fragmented QRS complexes in all leads, prominent R waves in the right precordial leads (V₁ through V₂), and Q waves in the lateral leads (I, aVL, and V₆).

What is the associated diagnosis?

A)  Left septal fascicular block

B)  Inferolateral infarction

C)  Right ventricular hypertrophy

D)  Duchenne muscular dystrophy

E)  Hypertrophic cardiomyopathy

Answer

B)  Inferolateral infarction

The broad differential diagnosis for tall R waves in the right precordial leads includes right ventricular (RV) hypertrophy, right bundle branch block, inferolateral wall infarction, hypertrophic cardiomyopathy, Duchenne muscular dystrophy, Wolff-Parkinson-White (WPW) syndrome, dextrocardia, left septal fascicular block (LSFB), rightward displacement of the heart, misplaced precordial leads, technical errors (such as inadequate high-pass and low-pass filters), and normal variant.^1-4

The ECG shows no evidence of right-axis deviation, right atrial enlargement, or RV strain pattern (that is, ST-segment depression or T-wave inversion in the right precordial or inferior leads) to support a diagnosis of RV hypertrophy.¹ The absence of a short PR interval and delta waves makes WPW syndrome unlikely. The diagnosis is not LSFB, because the pertinent ECG criteria include the loss of Q waves with an R pattern in the left-sided leads (I, aVL, V₅, and V₆), minimal QRS prolongation (<120 ms), and a prominent R pattern in V₁ through V₂ after other causes of prominent anterior forces had been excluded.² Of importance, the diffuse fragmented QRS complexes, defined as the presence of an R′ wave or notching of the R or S wave in a narrow QRS, suggest heterogeneous depolarization of the ventricular myocardium, indicating ischemia or a scar.

Clinically, the patient exhibited no features of muscular dystrophy on examination. His chest radiograph showed no dextrocardia or displacement of the heart. Of note, an echocardiogram showed a severely reduced left ventricular ejection fraction of 0.25 to 0.29, akinesis and thinning of the inferolateral wall, and hypokinesis and normal thickness of the other walls. The RV was mildly enlarged and hypokinetic, although without hypertrophy.

The combination of Q waves in the lateral leads, diffuse fragmented QRS complexes, remarkably tall R waves in leads V₁ through V₂, and the patient’s history of coronary artery disease is most consistent with a chronic inferolateral infarction. However, in the absence of chronic ischemic heart disease, the diagnosis of hypertrophic cardiomyopathy should be considered, because a tall R pattern in V₁ through V₂ can also result from septal depolarization related to prominent asymmetric septal hypertrophy.

References

1. Hancock EW, Deal BJ, Mirvis DM, Okin P, Kligfield P, Gettes LS, et al. AHA/ACCF/HRS recommendations for the standardization and interpretation of the electrocardiogram: part V: electrocardiogram changes associated with cardiac chamber hypertrophy: a scientific statement from the American Heart Association Electrocardiography and Arrhythmias Committee, Council on Clinical Cardiology; the American College of Cardiology Foundation; and the Heart Rhythm Society. Endorsed by the International Society for Computerized Electrocardiology. J Am Coll Cardiol 2009;53(11):992-1002.
2. Bayés de Luna A, Wagner G, Birnbaum Y, Nikus K, Fiol M, Gorgels A, et al. A new terminology for left ventricular walls and location of myocardial infarcts that present Q wave based on the standard of cardiac magnetic resonance imaging: a statement for healthcare professionals from a committee appointed by the International Society for Holter and Noninvasive Electrocardiography. Circulation 2006;114(16):1755-60.
3. Bayés de Luna A, Riera AP, Baranchuk A, Chiale P, Iturralde P, Pastore C, et al. Electrocardiographic manifestation of the middle fibers/septal fascicle block: a consensus report. J Electrocardiol 2012;45(5):454-60.
4. Bayés de Luna A, Rovai D, Pons Llado G, Gorgels A, Carreras F, Goldwasser D, Kim RJ. The end of an electrocardiographic dogma: a prominent R wave in V1 is caused by a lateral not posterior myocardial infarction-new evidence based on contrast-enhanced cardiac magnetic resonance-electrocardiogram correlations. Eur Heart J 2015;36(16):959-64.

https://doi.org/10.14503/THIJ-19-7056