A screw-type pacemaker lead implanted in the right atrium perforated the ascending aorta.

BACKGROUND: Perforation by pacemaker leads, although rare, is a complication reported since the introduction of pacemaker therapy. Although historically reported frequencies were as high as 5%, recent reports have cited frequencies ranging from 1 to 2%. We report a case where a screw-type atrial lead slightly penetrated the right atrial wall, causing chronic abrasion of the ascending aorta, resulting in shock. CASE PRESENTATION: A 54-year-old male presented with dilated cardiomyopathy diagnosed at 40 years of age when he developed decompensated heart failure. Despite ongoing treatment, his heart failure worsened, leading to hospitalization at the age of 54. During his hospital stay, he experienced cardiac arrest that required cardiopulmonary resuscitation, followed by a return of spontaneous circulation. He was subsequently transferred to our institution after initiation of venoarterial extracorporeal membrane oxygenation (VA-ECMO) and an intra-aortic balloon pump (IABP). Echocardiography revealed an ejection fraction of 25%, left ventricular end-diastolic diameter of 60 mm, and severe mitral regurgitation (MR). Transcatheter mitral valve repair was performed to treat severe MR, followed by implantation of a cardiac resynchronization therapy defibrillator (CRT-D). Three months later, the patient was brought to our emergency department by ambulance because of hypotension. Contrast-enhanced computed tomography revealed pericardial effusion causing cardiac tamponade, necessitating emergency pericardial decompression via left fourth intercostal mini-thoracotomy and drain placement. Upon transfer to the intensive care unit, 1200 mL of blood was drained from the chest tube, prompting a return to the operating room for a median sternotomy. It was discovered that the pacemaker lead on the left side of the right atrium had slowly eroded into the aorta, leading to perforation. The ascending aorta was repaired and hemostasis was achieved; the patient recovered uneventfully and was discharged on postoperative day 18. CONCLUSIONS: The pacemaker lead perforated the right atrium; chronic abrasion of the lead against the ascending aorta resulted in bleeding from the ascending aorta 3 months later.

Enhanced nuclear localization of phosphorylated MLKL predicts adverse events in patients with dilated cardiomyopathy.

AIMS: The role of necroptosis in dilated cardiomyopathy (DCM) remains unclear. Here, we examined whether phosphorylation of mixed lineage kinase domain-like protein (MLKL), an indispensable event for execution of necroptosis, is associated with the progression of DCM. METHODS AND RESULTS: Patients with DCM (n = 56, 56 ± 15 years of age; 68% male) were enrolled for immunohistochemical analyses of biopsies. Adverse events were defined as a composite of death or admission for heart failure or ventricular arrhythmia. Compared with the normal myocardium, increased signals of MLKL phosphorylation were detected in the nuclei, cytoplasm, and intercalated discs of cardiomyocytes in biopsy samples from DCM patients. The phosphorylated MLKL (p-MLKL) signal was increased in enlarged nuclei or nuclei with bizarre shapes in hypertrophied cardiomyocytes. Nuclear p-MLKL level was correlated negatively with septal peak myocardial velocity during early diastole (r = -0.327, P = 0.019) and was correlated positively with tricuspid regurgitation pressure gradient (r = 0.339, P = 0.023), while p-MLKL level in intercalated discs was negatively correlated with mean left ventricular wall thickness (r = -0.360, P = 0.014). During a median follow-up period of 3.5 years, 10 patients (18%) had adverse events. To examine the difference in event rates according to p-MLKL expression levels, patients were divided into two groups by using the median value of nuclear p-MLKL or intercalated disc p-MLKL. A group with high nuclear p-MLKL level (H-nucMLKL group) had a higher adverse event rate than did a group with low nuclear p-MLKL level (L-nucMLKL group) (32% vs. 4%, P = 0.012), and Kaplan-Meier survival curves showed that the adverse event-free survival rate was lower in the H-nucMLKL group than in the L-nucMLKL group (P = 0.019 by the log-rank test). Such differences were not detected between groups divided by a median value of intercalated disc p-MLKL. In δ-sarcoglycan-deficient (Sgcd-/- ) mice, a model of DCM, total p-MLKL and nuclear p-MLKL levels were higher than in wild-type mice. CONCLUSION: The results suggest that increased localization of nuclear p-MLKL in cardiomyocytes is associated with left ventricular diastolic dysfunction and future adverse events in DCM.

Early Detection of Cardiac Amyloidosis in Transthyretin Mutation Carriers.

Diagnostic strategies for symptomatic transthyretin (ATTR) cardiac amyloidosis showing typical morphological features such as increased ventricular wall thickness and myocardial injury such as an elevation in serum troponin T level have been established, but those for subclinical cardiac amyloidosis are limited. In the era when effective therapies to suppress/delay progression of ATTR cardiac amyloidosis are available, early detection of cardiac involvement plays a crucial role in appropriate decision-making for treatment in TTR mutation carriers who have a family history of heart failure and death due to ATTR amyloidosis. Findings of three cases with known pathogenic transthyretin (TTR) mutations (p.Ser70Arg, p.Phe53Val, and p.Val50Met) and family histories of death for amyloidosis were presented. Two cases were asymptomatic, and a case carrying p.Phe53Val had gastrointestinal symptoms and autonomic neuropathy. Levels of plasma N-terminal fragment of pro-B-type natriuretic peptide and troponin T were within normal ranges in all cases, but results of cardiac magnetic resonance (CMR) and bone scintigraphy clearly revealed the presence of cardiac involvement in all cases, even in a case without echocardiographic abnormalities including left ventricular hypertrophy and relative apical sparing of longitudinal strain shown by two-dimensional speckle-tracking echocardiography. Electrocardiography revealed modest abnormalities including reduced R wave amplitude in V2 and a trend toward left axis deviation in all cases. In conclusion, CMR, bone scintigraphy, and electrocardiography are useful for early detection of ATTR cardiac amyloidosis in TTR mutation carriers. The role of comprehensive cardiac assessment in the early detection of cardiac amyloidosis in TTR mutation carriers is discussed.