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Logo of bumcprocBaylor University Medical Center ProceedingsAbout the JournalBaylor Health Care SystemSubmit a Manuscript
Proc (Bayl Univ Med Cent). 2017 April; 30(2): 228–229.
PMCID: PMC5349839

Two causes in one patient for extremely low voltage on the electrocardiogram


An 80-year-old woman is described with two different causes (pericardial effusion and cardiac amyloidosis) for low QRS voltage on the electrocardiogram. Total 12-lead QRS voltage (from the peak of the R wave to the nadir of either the Q or the S wave, whichever is deeper) was only 34 mm (10 mm standard in all leads), the lowest we have encountered among 331 previously reported patients with 10 different cardiac conditions.

Among the causes of extremely low voltage on the electrocardiogram are large pericardial effusions and cardiac amyloidosis. The occurrence of both conditions in the same patient can lead to extremely low voltage on the electrocardiogram. The occurrence of such a situation prompted this report.


An 80-year-old woman with dementia was hospitalized because of worsening confusion and lower leg edema. She was known to have systemic hypertension and diabetes mellitus. She was in no acute distress. Her blood pressure was 85/60 mm Hg. Her body mass index was 18 kg/m2. No abdominal organs or subcutaneous lymph nodes were palpated. The electrocardiogram showed total 12-lead QRS voltage of 17 mm (standard ≈ 20 mm; double standard) (Figure 1). An echocardiogram disclosed pericardial effusion, thickened right and left ventricular walls, and low (≈20%) ejection fraction (Figure 2). Both ventricular cavities were of normal size.

Figure 1.
Electrocardiogram in the patient described. The standard is 20 mm, rather than the usual 10 mm.
Figure 2.
Transthoracic echocardiographic views—(a) parasternal short-axis view, (b) short-axis parasagittal view, and (c) apical four-chamber view—showing a brightly echogenic myocardium, thickened right ventricular and left ventricular walls, ...


Total 12-lead QRS voltage was introduced in 1982 as a means to predict the presence of left ventricular hypertrophy (1) (Figure 3). Subsequently, total 12-lead QRS voltage has been described in 10 different disease states involving 331 patients and compared in all to heart weight (2). It has been found to be a better predictor of left ventricular hypertrophy than any previous criteria.

Figure 3.
Various QRS complexes showing how each was measured. Reproduced from Siegel and Roberts (1) with permission of the authors and the publisher.

The concept of low QRS voltage was described initially when only three electrocardiographic leads were available. The 12-lead total QRS voltage has rarely been employed as an indicator of low QRS voltage. Among the 10 conditions in which total QRS voltage was measured and reported, those with the lowest voltage included cardiac amyloidosis, 58–199 mm (mean 104); cardiac adiposity, 73–210 mm (mean 120); and the carcinoid syndrome, 48–227 mm (mean 117). The lowest total 12-lead QRS voltage among the previously described 331 patients was 58 mm. Thus, to have an electrocardiographic total 12-lead QRS voltage of only 34 mm, as in the present patient, is indeed unusual.

A limitation of the present report is the lack of anatomic confirmation of cardiac amyloidosis. The echocardiogram, however, is virtually diagnostic of extensive cardiac amyloidosis.


1. Siegel RJ, Roberts WC. Electrocardiographic observations in severe aortic valve stenosis: correlative necropsy study to clinical hemodynamic, and ECG variables demonstrating relation of 12-lead QRS amplitude to peak systolic transaortic pressure gradient. Am Heart J. 1982;103(2):210–221. [PubMed]
2. Roberts WC, Filardo G, Ko JM, Siegel RJ, Dollar AL, Ross EM, Shirani J. Comparison of total 12-lead QRS voltage in a variety of cardiac conditions and its usefulness in predicting increased cardiac mass. Am J Cardiol. 2013;112(6):904–909. [PubMed]

Articles from Proceedings (Baylor University. Medical Center) are provided here courtesy of Baylor Health Care System