ABSTRACT
A 78-year-old male patient with complete atrioventricular block underwent an uncomplicated pacemaker implantation. After 24 h, he presented acute chest pain, dyspnea, ST-segment-elevation in the anterior leads, left ventricular apical ballooning, and an ejection fraction of 35%. His coronary angiogram was normal. Within 2 days, his symptoms and electrocardiogram (ECG) abnormalities disappeared, while wall motion abnormalities recovered after 6 weeks. A diagnosis of takotsubo syndrome (TTS) was made. Pacemaker implantation has been described as a potential trigger for TTS. The clinical picture exhibits some peculiarities, including a higher percentage of men and asymptomatic patients and challenging ST-segment interpretation of paced ECGs. It is unclear whether pathophysiologic mechanisms are different compared to other forms of TTS and whether the acute initiation of ventricular pacing plays a role.
ABSTRACT
AIMS: Cardiac amyloidosis remains a great challenge for the cardiologist. One of the three main aetiological forms, transthyretin-related hereditary amyloidosis (ATTRm), can present with several phenotypes, depending mainly on the specific mutation. We aimed to characterize the phenotype of patients with ATTRm due to Ile68Leu mutation, comparing them to patients with wild-type transthyretin amyloidosis (ATTRwt). METHODS AND RESULTS: Data of 67 Ile68Leu ATTRm patients from two Italian referral centres (Bologna and Florence) were retrospectively analysed and compared to those of 82 ATTRwt patients. Fifty-five unaffected mutation carriers were also analysed. Cumulative disease onset was 50% at age 71. A total of 56/67 (84%) patients had a predominantly cardiac phenotype at presentation with concentric increase in left ventricular wall thickness [median 17 mm], and normal or near normal left ventricular ejection fraction (79% of patients). Low QRS voltages were present only in 29% of patients but voltage/mass ratio was low (0.5). Carpal tunnel syndrome was noted in 43%. The overall phenotypic profile was similar to ATTRwt but Ile68Leu ATTRm patients typically presented younger (median 71 vs. 78 years) and were more likely to have (mild) symptomatic neurological involvement (19% vs. 2%). Male prevalence was 44% in unaffected mutation carriers and 78% in affected patients. Age-adjusted survival was comparable between groups. CONCLUSIONS: Ile68Leu ATTRm is a cause of familial amyloidotic cardiomyopathy endemic in central-northern Italy and presents as hypertrophic/restrictive cardiomyopathy quite similar to ATTRwt. Male preponderance is present in affected patients but not in unaffected mutation carriers. Age-adjusted survival is similar to ATTRwt.