Case Presentation

An 8.8-pound infant of a diabetic mother with prenatally suspected congenital heart disease was delivered via caesarean section at 35+2 weeks gestation and immediately intubated for severe hypoxemia. Initial transthoracic echocardiogram (TTE) demonstrated double inlet left ventricle (DILV) with a moderate sized bulboventricular foramen (BVF) and normally related great arteries, aka Holmes heart (Figure 1A-1B, Video 1). Additionally, there was severe biventricular hypertrophy (Figure 1C, Video 1), which confounded the initial echocardiographic diagnosis in multiple ways: creating the appearance of a more restrictive BVF (Figure 1D), a somewhat narrowed left ventricular outflow tract (LVOT, Figure 1E) and severe, bilateral atrioventricular valve regurgitation (AVVR, Figure 1A), the latter of which prompted the question of underlying cardiomyopathy.

Figure 1A: DILV. 2D and Color TTE, Four chamber view demonstrates a right sided right atrium and left sided left atrium with their two respective atrioventricular valves that both empty into a dilated, left-sided morphologic left ventricle. The Color panel shows severe atrioventricular valve regurgitation, which when taken with the severe hypertrophy prompted consideration of a possible underlying cardiomyopathy.

Figure 1B: Outflow tracts. 2D and Color TTE, Subcostal long axis view shows the normally related great artery relationship: the more anterior pulmonary artery arising from the posterior right ventricle and the more posterior aorta arising from the anterior left ventricle.

Video 1: DILV: 2D, TTE 4C Posterior to anterior sweep demonstrating the right and left atrioventricular valves both emptying into a large, dilated, left-sided morphologic left ventricle. The aorta is seen arising from this left ventricle first followed by a larger, more anterior pulmonary artery, which arises from a more posterior right ventricle, which is not well seen. There is severe biventricular hypertrophy, which is best appreciated during the sweep from the left ventricle into the aorta with near-complete obstruction of the left ventricular cavity.

Figure 1C: Severe hypertrophy. 2D TTE, PSAX view of the left ventricle at the level of the papillary muscles demonstrating the severe hypertrophy in the setting of being an infant of a diabetic mother. Of note, the very posterior right ventricle cannot be seen in this view.

Figure 1D: Bulboventricular foramen. 2D and Color TTE, PLAX view demonstrates flow across a moderate-sized bulboventricular foramen from the more anterior left ventricle to the posterior right ventricle, which can only be seen in this view. There is severe biventricular hypertrophy, which in this view is best seen in the free walls of the right and left ventricles.

Figures 1E: Left ventricular outflow tract. 2D and Color TTE, PLAX and 5C view showing the narrow appearance of the left ventricular outflow tract in the setting of the hypertrophy of the interventricular septum. The actual aortic valve and sub-aortic area measured normal for body surface area.

Over the next twelve days, the infant developed multiple episodes of ventricular tachyarrhythmias, and failed to wean respiratory support or tolerate enteral feeds. Repeat imaging revealed a new finding of discrete, distal arch obstruction that was confirmed by computed cardiac tomography (CCT, Figure 1F). In the interim, the other prior findings of a restrictive BVF, narrow LVOT, and severe AVVR all resolved while the biventricular hypertrophy improved (Vedio 2).

Figure 1F: Coarctation of the aorta. Cardiac CT demonstrating a discrete coarctation, demarcated by a yellow star, which presented later in the patient’s course once the patent ductus arteriosus had closed.

Video 2: Pre-operative Glenn: 2D, TTE subcostal sweep demonstrating improved biventricular hypertrophy with normal biventricular systolic function, mild LAVV regurgitation, obstructed aortic outflow and flow acceleration through the pulmonary outflow secondary to pulmonary artery band placement.

The patient underwent end-to-end anastomosis via lateral thoracotomy and was ultimately discharged home with oxygen saturations in the mid-80s after a final echocardiogram demonstrated mild restriction through the BVF and mild to moderate pulmonary stenosis, the combination of which provided a well-balanced circulation.

Over the next few months, the biventricular hypertrophy resolved, and the patient underwent a bidirectional Glenn when he developed persistent oxygen desaturations below 75%.

Discussion

While DILV is the most common form of univentricular AV connection, the anatomic variant known as the Holmes heart is considerably rare, comprising ~15% of all cases [1]. First described in 1824 by Dr. Andrew F. Holmes, this lesion was re-inspected in 1901 by Maude E. Abbott as cor trilocular biatriatum [1-2]. Since then, only a few isolated cases have been reported and almost all cases have been associated with right-sided obstruction secondary to the relationship of the pulmonary outflow to the outlet foramen [2-3].

We present a unique case of Holmes’s heart with both right and left-sided obstruction, the latter of which required early surgical intervention. What’s more, the presence of severe, biventricular hypertrophy further complicated the patient’s initial diagnostic picture, which in turn evolved over time.

Typically, the management of Holmes’s heart depends on the degree of restriction across the BVF: varying from ductal dependency requiring an aorto-pulmonary shunt to unrestrictive pulmonary blood flow requiring a pulmonary artery band [3]. In this patient’s case, the management strategy evolved with the echocardiographic findings: starting with an esmolol drip to help manage the subendocardial hypoperfusion followed by an end-to-end anastomosis to address the coarctation and ultimately the decision to forgo pulmonary artery banding due to the wellbalanced circulation that resulted from mild restriction of the BVF and pulmonary outflow.

So, we learn (as Holmes would have said himself) to appreciate not just the rarity of a diagnosis, but its evolution over time-after all, looks can be deceiving, so better to not just see, but observe.

Disclosures: The author has nothing to disclose.

Funding: No funding was used for this study.

References

1. Anderson RH, Lenox CC, Zuberbuhler JR, Ho SY, Smith A, et al. (1983) Double-inlet left ventricle with rudimentary right ventricle and ventriculoarterial concordance. Am J Cardiol 52(5): 573-7.
2. Dobell AR, Van Praagh R (1996) The Holmes heart: historic associations and pathologic anatomy. Am Heart J 132(2 Pt 1): 437-45.
3. Skaff AM, Parra DA, Soslow JH, Shuplock JM (2023) Association of Bulboventricular Foramen Size and Need for Early Intervention in Infants with Tricuspid Atresia or Double-Inlet Left Ventricle with Normally Related Great Arteries. J Am Soc Echocardiogr 36(3): 327332.