Right Ventricle Involvement by Glycogen Storage Cardiomyopathy (PRKAG2): Standard and Advanced Echocardiography Analyses

BACKGROUND

PRKAG2 syndrome is a rare, early-onset autosomal dominant inherited disease. We aimed to describe the right ventricle (RV) echocardiographic findings using two and three-dimensional (2D and 3D) modalities including myocardial deformation indices in this cardiomyopathy. We also aimed to demonstrate whether this technique could identify changes in RV function that could distinguish any particular findings.

METHODS

Thirty patients with genetically proven PRKAG2 (R302Q and H401Q), 16 (53.3%) males, mean age 39.1 ± 15.4 years, underwent complete echocardiography examination. RV-focused, 4-chamber view was acquired for 2D and 3D measurements. Student's t or Wilcoxon-Mann-Whitney tests were used to compare numerical variables between 2 groups, and p < 0.05 was considered significant.

RESULTS

Twelve patients (40%) had a pacemaker implanted for 12.4 ± 9.9 years. RV free wall mean diastolic thickness was 7.9 ± 2.9 mm. RV 4-chamber longitudinal strain (RV4LS), including the free wall and interventricular septum, was -17.3% ± 6.7%, and RV free wall longitudinal strain (RVFWLS) was -19.1% ± 8.5%. The RVFWLS apical ratio measured 0.63 ± 0.15. Mean RV 3D ejection fraction (EF) was 42.6% ± 10.9% and below normal limits in 56.7% of patients. Positive correlation occurred between RV 3DEF, RV4LS, and RVFWLS, especially for patients without a pacemaker (p = 0.006).

CONCLUSION

RV involvement in PRKAG2 syndrome is frequent, occurring in different degrees. Echocardiography is a valuable tool in detecting RV myocardial abnormalities in this condition. The use of 2D RV4LS, RVFWLS, and 3DEF offers reliable indicators of RV systolic dysfunction in this rare, challenging cardiomyopathy.

Percutaneous Removal of Cardiac Leads in a Single Center in South America

BACKGROUND

In the last decade, the number of cardiac electronic devices has risen considerably and consequently the occasional need for their removal. Concurrently, the transvenous lead removal became a safe procedure that could prevent open-heart surgery.

OBJECTIVE

The primary objective of this study was to describe the successful performance and the complication rates of pacemaker removals in a Brazilian public hospital. Our secondary aim was to describe the variables associated to successes and complications.

METHODS

A retrospective case series was conducted in patients submitted to pacemaker removal in a Brazilian public hospital from January 2013 to June 2018. Removal, explant, extraction, success and complication rates were defined by the 2017 Heart Rhythm Society Guideline. Categorical variables were compared using x2 or Fisher's tests, while continuous variables were compared by unpaired tests. A p-value of 0.05 was considered statistically significant.

RESULTS

Cardiac device removals were performed in 61 patients, of which 51 were submitted to lead extractions and 10 to lead explants. In total, 128 leads were removed. Our clinical success rate was 100% in the explant group and 90.2% in the extraction one (p=0.58). Major complications were observed in 6.6% patients. Procedure failure was associated to older right ventricle (p=0.05) and atrial leads (p=0,04). Procedure duration (p=0.003) and need for blood transfusion (p<0,001) were associated to more complications.

CONCLUSION

Complications and clinical success were observed in 11.5% and 91.8% of the population, respectively. Removal of older atrial and ventricular leads were associated with lower success rates. Longer procedures and blood transfusions were associated with complications.

Cardiac resynchronization therapy in patients with heart failure: systematic review

CONTEXT AND OBJECTIVE

Cardiac resynchronization therapy (CRT) has emerged as the predominant electrical treatment strategy for patients on pharmacological therapy who present heart failure with wide QRS and low ejection fraction. The objective of this study was to investigate whether cardiac resynchronization therapy improved mortality and morbidity among patients with heart failure.

METHODS

This was a systematic review using the Cochrane Collaboration's methodology. The online search strategy included the Cochrane Library, Medline (Medical Literature Analysis and Retrieval System Online), Lilacs (Literatura Latino-Americana e do Caribe em Ciências da Saúde) and cardiology congresses from 1990 to 2006. The criteria for considering studies for this review were as follows:-types of studies: randomized controlled trials; types of interventions: cardiac resynchronization therapy compared with other therapies; types of participants: patients with heart failure with low ejection fraction and wide QRS; outcomes: death or hospitalization.

RESULTS

Seven trials met the selection criteria. The risk of death due to congestive heart failure was nonsignificant: relative risk (RR), 0.79; 95% confidence interval (CI): 0.60 to 1.03. There was an absolute risk reduction of 4% in all-cause mortality for the experimental group [RR 0.70; CI: 0.60 to 0.83; number needed to treat (NNT) 25]; sudden cardiac death showed a statistically significant difference favoring the experimental group, with absolute risk reduction of 1% (CI: 0.46 to 0.96; RR 0.67; NNT 100). There was an absolute risk reduction of 9% for hospitalization due to heart failure (RR 0.64; CI: 0.50 to 0.80; NNT 11) in the experimental group.

CONCLUSIONS

Patients receiving CRT had a significantly lower risk of hospitalization due to heart failure, but death rates due to heart failure were similar.