Pendulum Heart in Congenital Absence of the Pericardium
A 20-year-old man with pectus excavatum status after GORE-TEX mesh placement presented because of symptomatic dyspnea on exertion and stabbing chest pain. On physical examination, mild residual pectus excavatum and laterally displaced apical impulse were observed, with otherwise normal physical examination results. An ECG showed right axis deviation with incomplete right bundle branch block and poor R wave progression in the precordial leads (Figure 1A). Chest x-ray showed leftward position of the heart and flattening and elongation of the left heart border. A lucent area between the aorta and pulmonary artery secondary to lung interposition was noticed (Figure 1B).
The patient was referred for stress echocardiography for evaluation of ongoing atypical chest pain. The rest transthoracic echocardiogram images were consistent with congenital absence of the pericardium. The right ventricle seemed enlarged (Figure 2), and pathognomonic appearance of “teardrop heart,” with elongated atria and widened ventricles, was demonstrated (Movie I of the online-only Data Supplement). M mode examination showed paradoxical systolic and diastolic septal motion (Figure 3). Pulse Doppler pulmonary vein flow evaluation demonstrated reduced systolic flow and systolic-to-diastolic flow ratio (Figure 4). Stress images showed erratic pendulum-like movement of the heart, accompanied by continuous QRS axis change (Figure 5, Movie II of the online-only Data Supplement). Interestingly, strain and torsion measured by 2-dimensional speckle tracking imaging, with use of velocity vector imaging technique, were abnormal, and global longitudinal strain and torsion were reduced (Movie III of the online-only Data Supplement). The patient received a diagnosis of complete absence of the pericardium, which was confirmed by computed tomography of the chest (Figure 6).
Congenital absence of the pericardium is an uncommon cardiac defect with variable clinical presentation.1 Detection of this malformation is clinically relevant because of potential complications such as fatal myocardial strangulation, myocardial ischemia, tricuspid regurgitation, and sudden death. In this case we show for the first time, as far as we are aware, the exaggerated “pendulum” movement of the heart during effort, which has previously been described only in patients with large pericardial effusion or severe blunt trauma to the chest resulting in pericardial rupture. This may shed light on the common clinical presentation of paroxysmal exertional and postural sharp stabbing chest pain. Furthermore, we describe here for the first time, as far as we are aware, the beat-to-beat morphological QRS changes during stress electrocardiography, which has previously been described only with large pericardial effusions. Torsional strain was grossly abnormal, in concordance with previous reports.2
Echocardiography may accurately identify abnormalities in myocardial motion, appearance, and hemodynamics that strongly imply the diagnosis.3 In the present case, the diagnosis was suggested by a myriad of echocardiographic abnormalities, including levoposition of the heart with laterally displaced parasternal windows, “teardrop heart” secondary to the absence of normal tethering and shaping forces applied by the normal pericardium, and apparent paradoxical septal motion in M mode examination, assumed to be due to exaggerated translational motion. Furthermore, the reduced pulmonary systolic flow was assumed to be secondary to loss of the normal decrease in pericardial pressure during ventricular ejection.4
In conclusion, the diagnosis of congenital absence of the pericardium should be suspected when the characteristic echocardiographic features are present. In addition, although nonspecific to congenital absence of the pericardium, strain measurement by speckle tracking imaging has the potential to overcome bothersome translational movement and may aid in defining the role of the pericardium in left ventricular torsion or longitudinal deformation. Furthermore, abnormal stress electrocardiographic and echocardiographic responses may aid in the diagnostic evaluation of these patients.
The authors thank Mark E. Zangs, Timothy Seelinger, and Gretchen A. Schiesser for technical assistance.
The online-only Data Supplement is available with this article at http://circ.ahajournals.org/cgi/content/full/121/10/1272/DC1.