Identification of stimulation site of pacemaker lead using tissue tracking method.

PURPOSE: We aimed to identify the electrical stimulation sites of pacemaker leads using a tissue tracking method of tissue Doppler imaging. METHODS: The study group consisted of 30 patients who had undergone permanent pacemaker implantation. During tissue Doppler imaging, the initial contraction site was seen as a red area stimulated by the pacemaker lead. This red area was analyzed precisely using time-distance curves generated by tissue tracking. RESULTS: The initial contraction site of the myocardium was located in the interventricular septum in seven patients and in the apical portion of the right ventricle in 11 patients. Furthermore, analysis of time-distance curves demonstrated that one point within the red area started to move earlier than the others. CONCLUSION: The site of electrical stimulation within the myocardium can be determined from the time-distance curves generated by the tissue tracking method.

Isolated noncompaction of the left ventricular myocardium in an elderly patient.

Noncompaction of the ventricular myocardium (NVM) is a rare disorder of endomyocardial morphogenesis characterized by numerous, prominent trabeculations and deep intertrabecular recesses. It is commonly associated with congenital heart disease, but the isolated form (INVM) is not associated with other structural heart diseases. Clinical reports of INVM have been limited to a few case reports and small series of pediatric patients. INVM is considered to be a form of congenital abnormal endomyocardial morphogenesis caused by abnormal cessation of the embryonic development of the ventricular myocardium; most reported cases have been pediatric patients, and autopsy cases of elderly patients have been quite rare. In the present case, an elderly female had INVM associated with severely disturbed left ventricular (LV) function and an enlarged left ventricle similar to dilated cardiomyopathy. The echocardiogram showed prominent trabeculations and deep intertrabecular recesses of the LV walls, especially in the posterior and apical areas. LV contrast echocardiography revealed markedly protruberant trabeculations, which were also observed with computed tomography. Five years later, the patient died of refractory heart failure and ventricular fibrillation. The autopsy revealed numerous excessively prominent trabeculations in the LV myocardium, with deep intertrabecular recesses containing thrombi.

A case of double-chambered right ventricle associated with an interventricular septal aneurysm in an elderly patient.

Double-chambered right ventricle is a congential malformation caused by an anomalous muscle band obstructing the right ventricular outflow tract. Most reported cases of this condition have been diagnosed in infants, or adolescents. We encountered a 61-year-old woman with a double-chambered right ventricle, associated with a large interventricular septal aneurysm, which is a rare complication. The right ventricular obstruction was corrected with surgery.