Solitary Papillary Muscle Hypertrophy: A New Echo-Electrocardiographic Syndrome? A Case Report

Papillary muscles. Dark side of the heart: A simple approach for a forgotten structure

PURPOSE

Transthoracic echocardiography (TTE) is currently the election method for initial screening of left ventricular papillary muscles (PM). However, diagnosis of borderline PM hypertrophy with TTE is not always feasible due to cumbersome interpretation of different PM diameters and the absence of precise normal ranges in the literature. The objective of this study was to obtain TTE normal cutoff values and to describe convenient indexes of PM dimensions.

METHODS

Healthy volunteers with normal electrocardiogram were included for TTE assessment. Vertical (Vd) and horizontal (Hd) PM diameters were measured to obtain maximum diameter (Md) and areas of the anterolateral PM (APM) and posteromedial PM (PPM) to obtain PM total area (PMTA).

RESULTS

A total of 82 patients were screened, and 6 (7.3%) with bifid PM were excluded from analysis. APM and PPM had similar Vd (APM: 8.3 ± 1.2, PPM: 7.9 ± 1.1 mm² , P = NS) and Hd (APM: 8.2 ± 1.3, PPM: 8.3 ± 1.2 mm² , P = NS). Finally, Md (9 ± 1.2 mm; P95 = 11 mm) and PMTA (106.5 ± 24.2 mm² ; P95 = 150.8 mm² ) were obtained. Correlation between PMTA and Md was positive (P < .001), and out-of-range values for Md and PMTA were similar (2.6% vs 5.3%); there was excellent agreement between both indexes (K = 0.82).

CONCLUSIONS

Maximum diameter and PMTA are convenient indexes to describe PM dimensions. However, given the high equivalence between both indexes, we propose the use of Md due to its simplicity and ease of calculation. Our findings suggest that patients with any PM diameter ≥12 mm should be considered abnormal.

Possible association of papillary muscle hypertrophy with the genesis of J-waves

BACKGROUND

Although J-waves have been known to be associated with vulnerability to ventricular fibrillation, their electrophysiologic mechanism remains to be elucidated. The papillary muscles (PMs) of the left ventricle (LV) have been recognized as the target site of radiofrequency ablation for ventricular arrhythmias. However, the relationship between PM hypertrophy and J-waves has not been investigated.

OBJECTIVE

To investigate the electrocardiographic characteristics, including the J-waves, in patients with solitary PM hypertrophy.

METHODS

We studied 101 patients with PM hypertrophy without LV hypertrophy (PMH group) and 159 age- and sex-matched control subjects (control group). The parameters of the 12-lead electrocardiogram and the echocardiogram were compared between the two groups.

RESULTS

Compared with the control group, the PMH group had significantly higher incidence (15% vs. 33%, p=0.001) and amplitude (0.17±0.06mV vs. 0.28±0.17mV, p<0.01) of J-waves; significantly longer QRS, QTc, and JTc intervals (p=0.0001, p<0.0001, and p<0.05, respectively); significantly greater Sokolow-Lyon index (p<0.001); and significantly greater LV wall thickness and LV mass index (p<0.0001 for each). Multivariate logistic regression analysis showed that only the PM hypertrophy was an independent predictor of the presence of J-waves.

CONCLUSION

PM hypertrophy was related to the genesis of J-waves.

Mitral Hemi-Arcade: A Rare Variant of a Rare Disease

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A case of a healthy young male with chest pain and borderline electrocardiogram is presented.

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Imaging showed a mitral hemi-arcade with left ventricular outflow tract obstruction during exercise.

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Previously postulated mechanisms for this obstruction are reviewed in this article.

Isolated papillary muscle hypertrophy: A gap in our knowledge of hypertrophic cardiomyopathy?

Increased thickness of left ventricular walls is the predominant characteristic and one of the diagnostic criteria of hypertrophic cardiomyopathy (HCM). This case illustrates an uncommon but important finding of isolated hypertrophy of the papillary muscles (PMs), observed in a young woman in whom an abnormal electrocardiogram was initially detected. During the investigation isolated PM hypertrophy was identified. The structural characteristics of the PMs have received scant attention in this setting and there is little information in the literature on this entity, whose real prevalence and clinical significance remain to be determined. The available information relates solitary PM hypertrophy with an early form or a different pattern of HCM. In this case PM hypertrophy was only detected due to the finding of an abnormal electrocardiogram, which prompted further diagnostic tests and a search for possible etiologies.

Solitary accessory and papillary muscle hypertrophy manifested as dynamic mid-wall obstruction and symptomatic heart failure: diagnostic feasibility by multi-modality imaging

BACKGROUND

Solitary papillary muscle (PM) hypertrophy is an unique type of hypertrophic cardiomyopathy (HCM), which is characterized by predominant papillary muscle hypertrophy sparing the rest of other left ventricular segments. It has recently drawn our attention about the mechanism of left ventricular mid-cavity obstruction and the influence of pressure gradient in the left ventricular outflow tract (LVOT), thus carries clinical importance.

CASE PRESENTATION

We reported a symptomatic, 83-year-old woman who presented with dynamic, high resting left ventricle (LV) mid-wall gradient without obvious septal hypertrophy or systolic anterior motion (SAM). Subsequent real-time (RT) three-dimensional echocardiography (3DE) and cardiac magnetic resonance imaging (MRI) demonstrated large, hypertrophic accessory papillary muscles squeezing mid-cavity of left ventricle producing dynamic pressure gradient during systole in the absence of left ventricular wall anomalies.

CONCLUSION

We proposed that combined use of echocardiography particularly RT-3DE and cardiac magnetic resonance imaging (MRI) can accurately identify this specific type of hypertrophic cardiomyopathy without remarkable traditional features.

Type III hemifacial microsomia in a kitten

The case described herein presented with craniofacial malformations resembling hemifacial microsomia (HFM), a congenital disorder described in humans. To our knowledge, this is the first reported case of HFM in a domestic cat.

Bigeminy and the bifid papillary muscle

Various structural anomalies of the left ventricular papillary muscles have been observed in recent years. Many of these have been linked to electrocardiographic aberrations. Recently two reports have appeared where the base of the posterior papillary muscle was identified as the source of frequent premature ventricular complexes. In some of these patients these frequent premature ventricular complexes have led to left ventricular dysfunction. In this report a newly discovered structural variant of the anterior papillary muscle is described--the bifid papillary muscle. Furthermore, it is proposed that this bifid papillary muscle is the source of frequent ventricular premature complexes, presenting as bigeminy in a patient with normal left ventricular function.

The Double U Wave—Should the Electrocardiogram be Interpreted Echocardiographically?

The U wave is still an electrocardiographic deflection of enigmatic origin. Numerous hypotheses on its origin have been formulated, but to date none has been conclusively proven. Recently, a report described the first case of bifid (or notched) U waves. Until then this phenomenon has only been described in the T wave. This is the first report of double U waves—two separate deflections, ascribed to an accessory papillary muscle.

The accessory papillary muscle with inferior J-waves--peculiarity or hidden danger?

Originally described in 1953, today the so-called J-wave is the source of much controversy. As a marker of so-called "early repolarization", this variant has been regarded as a totally benign variant since the 1960's. However, since then a wealth of data have indicated that the J-wave may be a marker of a highly arrhythmogenic substrate with a resultant high risk of sudden cardiac death.

In this case report a case of an accessory papillary muscle with a prominent J-wave is described. This may be the first of many possible cases where papillary muscle variants may be the cause of the J-wave.