Clinical outcomes of catheter ablation for atrial fibrillation, atrial flutter, and atrial tachycardia in wild-type transthyretin amyloid cardiomyopathy: a proposed treatment strategy for catheter ablation in each arrhythmia.

AIMS: Wild-type transthyretin amyloid cardiomyopathy (ATTRwt-CM) is often accompanied by atrial fibrillation (AF), atrial flutter (AFL), and atrial tachycardia (AT), which are difficult to control because beta-blockers and antiarrhythmic drugs can worsen heart failure (HF). This study aimed to investigate the outcomes of catheter ablation (CA) for AF/AFL/AT in patients with ATTRwt-CM and propose a treatment strategy for CA. METHODS AND RESULTS: A cohort study was conducted on 233 patients diagnosed with ATTRwt-CM, including 54 who underwent CA for AF/AFL/AT. The background of each arrhythmia and the details of the CA and its outcomes were investigated. The recurrence-free rate of AF/AFL/AT overall in ATTRwt-CM patients with multiple CA was 70.1% at 1-year, 57.6% at 2-year, and 44.0% at 5-year follow-up, but CA significantly reduced all-cause mortality [hazard ratio (HR): 0.342, 95% confidence interval (CI): 0.133-0.876, P = 0.025], cardiovascular mortality (HR: 0.378, 95% CI: 0.146-0.981, P = 0.045), and HF hospitalization (HR: 0.488, 95% CI: 0.269-0.889, P = 0.019) compared with those without CA. There was no recurrence of the cavotricuspid isthmus (CTI)-dependent AFL, non-CTI-dependent simple AFL terminated by one linear ablation, and focal AT originating from the atrioventricular (AV) annulus or crista terminalis eventually. Twelve of 13 patients with paroxysmal AF and 27 of 29 patients with persistent AF did not have recurrence as AF. However, all three patients with non-CTI-dependent complex AFL not terminated by a single linear ablation and 10 of 13 cases with focal AT or multiple focal ATs originating beyond the AV annulus or crista terminalis recurred even after multiple CA. CONCLUSION: The outcomes of CA for ATTRwt-CM were acceptable, except for multiple focal AT and complex AFL. Catheter ablation may be aggressively considered as a treatment strategy with the expectation of improving mortality and hospitalization for HF.

Clinical, electrocardiographic, and echocardiographic parameters associated with the development of pacing and implantable cardioverter-defibrillator indication in patients with transthyretin amyloid cardiomyopathy.

AIMS: This study aimed to identify factors for attention leading to future pacing device implantation (PDI) and reveal the necessity of prophylactic PDI or implantable cardioverter-defibrillator (ICD) implantation in transthyretin amyloid cardiomyopathy (ATTR-CM) patients. METHODS AND RESULTS: This retrospective single-center observational study included consecutive 114 wild-type ATTR-CM (ATTRwt-CM) and 50 hereditary ATTR-CM (ATTRv-CM) patients, neither implanted with a pacing device nor fulfilling indications for PDI at diagnosis. As a study outcome, patient backgrounds were compared with and without future PDI, and the incidence of PDI in each conduction disturbance was examined. Furthermore, appropriate ICD therapies were investigated in all 19 patients with ICD implantation. PR-interval ≥220 msec, interventricular septum (IVS) thickness ≥16.9 mm, and bifascicular block were significantly associated with future PDI in ATTRwt-CM patients, and brain natriuretic peptide ≥35.7 pg/mL, IVS thickness ≥11.3 mm, and bifascicular block in ATTRv-CM patients. The incidence of subsequent PDI in patients with bifascicular block at diagnosis was significantly higher than that of normal atrioventricular (AV) conduction in both ATTRwt-CM [hazard ratio (HR): 13.70, P = 0.019] and ATTRv-CM (HR: 12.94, P = 0.002), whereas that of patients with first-degree AV block was neither (ATTRwt-CM: HR: 2.14, P = 0.511, ATTRv-CM: HR: 1.57, P = 0.701). Regarding ICD, only 2 of 16 ATTRwt-CM and 1 of 3 ATTRv-CM patients received appropriate anti-tachycardia pacing or shock therapy, under the number of intervals to detect for ventricular tachycardia of 16-32. CONCLUSIONS: According to our retrospective single-center observational study, prophylactic PDI did not require first-degree AV block in both ATTRwt-CM and ATTRv-CM patients, and prophylactic ICD implantation was also controversial in both ATTR-CM. Larger prospective, multi-center studies are necessary to confirm these results.

Comparison of electron microscopic findings and clinical presentation in three patients with mitochondrial cardiomyopathy caused by the mitochondrial DNA mutation m.3243A > G.

Mitochondrial cardiomyopathy can be described as a condition characterized by abnormal heart-muscle structure and/or function, secondary to mutations in nuclear or mitochondrial DNA. Its severity can range from subclinical to critical conditions. We presented three cases of mitochondrial cardiomyopathy with m.3243A > G mutation and compared the clinical manifestations with the histological findings for each of these cases. All cases showed cardiac hypertrophy, juvenile-onset diabetes mellitus, and hearing loss. Case 1 (43-year-old male) showed less cardiac involvement and shorter duration of mitochondrial disease-related symptoms than case 2 (67-year-old female) and case 3 (51-year-old male), who showed the most advanced cardiac condition and longest duration from the manifestation of heart failure. The histological findings revealed that cardiomyocytes from case 1 showed no hypertrophy and mitochondrial degeneration in electron microscopy. Alternatively, cases 2 and 3 showed hypertrophy in their cardiomyocytes, and mitochondrial degeneration (e.g. onion-like lesions, swollen cristae, and lamellar bodies) was most apparent in case 3. These results suggested that mitochondrial degeneration, as evaluated by electron microscopy, might be correlated with impaired heart function in patients with mitochondrial cardiomyopathy.

Left-dominant arrhythmogenic cardiomyopathy with a nonsense mutation in DSP.

A 74-year-old man had abnormal left ventricular (LV) function according to a perioperative test at a local hospital and was transferred to our institution for further evaluation and treatment. His electrocardiogram demonstrated the presence of premature ventricular contraction with a QRS complex of the right bundle branch block type and superior axis. His echocardiography showed systolic dysfunction of the LV (LV ejection fraction, 44.6%). Cardiac computed tomography imaging revealed banded and patchy densities observed frequently from the middle to epicardial layer of the LV wall. Cardiac magnetic resonance imaging showed fat signals on fat-selective images and late gadolinium enhancement in the mid-wall to subepicardial layers in the LV myocardium. Endomyocardial biopsy revealed the histological presence of fibrofatty replacement. A genetic analysis revealed a nonsense mutation in the desmoplakin gene. Thus, he was diagnosed with left-dominant arrhythmogenic cardiomyopathy. To prevent fatal ventricular arrhythmias, an implantable cardioverter defibrillator was successfully implanted.

Wild-type transthyretin amyloid cardiomyopathy complicated by spinal canal stenosis, carpal tunnel syndrome, and rotator cuff tears: a case report.

BACKGROUND: Wild-type transthyretin amyloid cardiomyopathy (ATTRwt-CM) is receiving increasing attention due to the availability of novel treatment options. Carpal tunnel syndrome (CTS) and lumbar spinal canal stenosis are known early symptoms of transthyretin (TTR) amyloidosis preceding the cardiac involvement and are considered as 'Red Flags' for transthyretin amyloid cardiomyopathy (ATTR-CM). CASE SUMMARY: A 67-year-old man with a history of lumbar spinal canal stenosis for the last 10 years, right rotator cuff tears for the last 4 years, and bilateral CTS for the last 1 year was scheduled for orthopaedic surgery for lumbar spinal canal stenosis. Investigations revealed severe left ventricular hypertrophy and hypertroponinaemia, which were suggestive of cardiac amyloidosis. Cardiac magnetic resonance imaging and 99mTc-labelled pyrophosphate scintigraphy demonstrated positive findings for ATTR-CM. Transthyretin deposition was found in both the myocardium and the yellow ligamentum excised during surgery. There was no transthyretin mutation on genetic testing. The final diagnosis was ATTRwt-CM. DISCUSSION: Transthyretin deposition in the ligaments or tendons has been observed in a number of patients with CTS, spinal canal stenosis, and rotator cuff tears. These orthopaedic diseases are predictive for the future occurrence of ATTR-CM. In addition, the coexistence of these multiple diseases might strongly predict ATTR-CM. This knowledge needs to be shared with orthopaedicians and cardiologists for the early diagnosis of ATTR-CM.

Case of skin injuries due to stings by crown-of-thorns starfish (Acanthaster planci).

A case of skin injuries due to stings by crown-of-thorns starfish, Acanthaster planci, in a 53-year-old Okinawan woman is reported. She went to a beach to gather shellfish on 8 April 2001 and fell to the ground with her left palm on a crown-of-thorns starfish that happened to be close to her. She hurried to the emergency section of our hospital. An emergency doctor sterilized the wound and administered an antibiotic, an analgesic agent and an injection of a tetanus antitoxin. He tried to remove the remaining spines from the palm with great difficulty. Because swelling and subcutaneous indurations of the left palm had persisted thereafter, oral and topical administration of corticosteroid started on 13 April. Physical examination at the dermatology section revealed approximately 10 stab wounds of the left palm with pus, subcutaneous bleeding and many abrasions around them. X-rays of the left hand showed foreign bodies, 2-10 mm in size, located on the lesions. The patient was treated with a topical injection of 2 mg triamcinolone acetonide (Kenacort-A), diluted fivefold with 1% Xylocaine, once a week. Some of the foreign body granulomatous lesions improved but pain and subcutaneous indurations persisted in most of the lesions. Because the X-ray photographs showed many remaining spines, surgical excision to remove them was performed under local anesthesia 3 months after the injury. All the symptoms improved after the operation. Scanning electron microscopic examination of the spines revealed that their tips had fragile lattice-like structures.