Association Between Genetic Variation in the SCN10A Gene and Cardiac Conduction Abnormalities in Patients With Hypertrophic Cardiomyopathy.

Arrhythmias are associated with reduced quality of life and poor prognosis in patients with hypertrophic cardiomyopathy (HCM). Recent genome-wide association studies revealed that a nonsynonymous single nucleotide polymorphism, rs6795970, in the SCN10A gene was associated with the PR interval. We examined whether the PR prolonging allele (A allele) in the SCN10A gene may be associated with cardiac conduction abnormalities in HCM patients.We genotyped the polymorphism in 149 HCM patients. Conduction abnormalities were defined as first-degree heart block, bundle-branch block, and bifascicular heart block. Patients were divided into two groups: group A consisted of 122 patients (82%) without a conduction abnormality; and group B consisted of 27 patients (18%) with one or more cardiac conduction abnormalities. The frequency distribution of the SCN10A genotypes (G/G, G/A, and A/A) among the patients with HCM was 71%, 26%, and 3%, respectively. A cardiac conduction abnormality was documented in 9% with G/G and 40% with G/A or A/A. There was a significant difference in the genotype distribution between the two groups (P = 0.0002). In the dominant A allele model, there was a significant difference in genotypes between the two groups (P < 0.0001). In addition, the A allele remained significant after adjusting for other covariates in a multivariate model (odds ratio = 6.30 [95% confidence interval: 2.24 to 19.09], P = 0.0005).The rs6795970 in the SCN10A gene, which is reported to carry a high risk of heart block, might be associated with cardiac conduction abnormalities in HCM patients.

Ro52 autoantibody-positive women's experience of being pregnant and giving birth to a child with congenital heart block.

OBJECTIVE: congenital heart block may develop in the fetus of women with Ro/SSA autoantibodies. The aim of this study was to investigate how women expecting a child with congenital heart block (CHB) experienced their pregnancy and post-partum period. DESIGN, SETTING AND PARTICIPANTS: women giving birth to a child with CHB in Sweden during 2000-2009 were identified in a population-based manner and individually interviewed post-pregnancy using a semi-structured interview guide. The interviews (n=21) were audiotaped, transcribed verbatim and analysed by qualitative content analysis. FINDINGS: three categories emerged from the responses: learning, suspense and facing. Learning contained both learning about the child's heart block, but frequently also about autoantibody-positivity and a potential rheumatic diagnosis in the mother (16/21). The medical procedures and information differed considerably depending on the area of residence and who was encountered in the health-care system. In many cases, ignorance about this rare condition caused a delay in treatment and surveillance. Suspense described the women's struggle to cope with the feeling of guilt and that the child had a serious heart condition and might not survive the pregnancy. Facing included the post-partum period, leaving the hospital and adjusting to everyday life. The women had tended to put their pregnancies 'on hold', and some described that they needed prolonged time to bond with their newborn child. CONCLUSION: increased awareness and knowledge of CHB are needed to provide adequate care. Offering psychological support by a health-care professional to facilitate early bonding with the child should be considered. IMPLICATIONS FOR PRACTICE: there is a need for structured programs for surveillance of the pregnancies. Such programme should implement guidelines for the involved personnel in the chain of care and make relevant information accessible for the women and families.

[Heart disease in schizophrenia]. / Kardiale Erkrankung bei Schizophrenie.

A 63-year-old male patient diagnosed with chronic schizophrenia and characterized by formal disorders of thought with neologism and paranoid ideation, especially grandiose delusions and feelings of being influenced by radiation, is presented. At admission to psychiatric hospital, the patient reported attacks of weakness and dizziness, which he attributed to his feelings of alien influence. The diagnosis of cardiac disease with severe bradycardia could already be established by basic physical examination. Further diagnostic procedures (e.g., ECG) revealed symptomatic atrioventricular conduction defects (atrioventricular block III). After implantation of a cardiac pacemaker, the somatic symptoms vanished and the patient recovered completely in terms of physical condition.

Clinical relevance of loss of atrial sensing in patients with single lead VDD pacemakers.

During single lead VDD pacing, loss of atrial sensing is reported to be 2%-11% of patients in the literature. The impact on quality-of-life and exercise duration has never been established. This study tried to assess the clinical relevance of loss of atrial sensing in patients with single lead VDD pacemakers. Twenty-one patients with total AV block were studied 3 months after single lead VDD pacemaker implantation. During a 6-minute walk test, atrial undersensing was verified and adjusted to achieve undersensing in < 5% (group 1), 5%-10% (group 2), and > 10% (group 3). Patients were allocated to each group in a randomized double blind crossover design. At the end of each 2-month study period all patients underwent symptom limited treadmill exercise testing. Subjective assessment of exercise difficulty was made using the Borg score, and quality-of-life assessment was performed using the Health Status Questionnaire. Exercise duration significantly decreased in group 3 (228 +/- 50 s) as compared to group 1 (257 +/- 42 s) and group 2 (250 +/- 46 sec) with an increase in the Borg score. Quality-of-life was decreased for three subscales in group 3 as compared to group 1 and group 2. In conclusion, atrial undersensing of > 10% in patients with single lead VDD pacing was associated with a decrease in exercise duration and increase in the subjective severity score, in addition to a decrease in quality-of-life. Atrial undersensing of < 10% did not effect exercise test results or quality-of-life. Since all studies reported intact atrioventricular synchrony in > or = 90% of patients, loss of atrial sensing is of limited clinical importance in these patients.

Effect of restoration of AV synchrony on stroke volume, exercise capacity, and quality-of-life: can we predict the beneficial effect of a pacemaker upgrade?

The aim of this study was to assess to what extent patients with VVIR pacemakers and without overt symptoms of a pacemaker syndrome benefit from a pacemaker upgrade, and if a preoperative noninvasive measurement of the change in stroke volume (SV) could predict the effect of a pacemaker upgrade. The study group consisted of 20 (12 women, 8 men) VVIR patients with a mean age of 60 years. The indication for the first implantation was AV block in 13 patients and SSS in 7. The mean time of a ventricular pacing was 77 months. The objective (echocardiography, an exercise capacity) and the subjective (the quality-of-life) parameters investigated in patients during ventricular pacing were compared to results obtained 2 months and 1 year after a pacemaker upgrade. To assess preoperatively a change in a SV expected after upgrading, attempts were made to restore AV synchronization by the use of a transesophageal pacemaker. An increase in SV (from 5% to > 35%) during temporary AV resynchronization was observed in each patient. Values of SV increase correlated with those obtained 2 months (r = 0.65; P < 0.01) and 1 year (r = 0.66; P < 0.01) after an upgrade. Superior hemodynamics was associated with a significant improvement of an exercise capacity in both subgroups of patients. The most significant improvement in the quality-of-life was observed in patients with SSS. We did not find correlations between SV and the quality-of-life assessed 2 months (r = 0.043; NS) or 1 year (r = 0.02; NS) after an upgrade. In conclusion, a pacemaker upgrade performed after a long-term ventricular pacing resulted almost consistently in the improvement of hemodynamics and was associated with an increase of exercise capacity. In patients with SSS it was followed by the significant improvement of their quality-of-life. Such a relation was not observed in patients with AV block as some of them (especially those with VVIR pacemakers) felt quite well during ventricular pacing. The proposed preoperative echocardiographic evaluation may precisely predict the degree of hemodynamic improvement expected after a pacemaker upgrade.

Psychometric properties of Aquarel. a disease-specific quality of life questionnaire for pacemaker patients.

In cardiac pacing current clinical practice permits the use of ventricular or atrioventricular-synchronous pacemakers. However, it is not known which type of pacemaker results in superior clinical and patient outcomes. To date, there is no feasible and validated disease-specific questionnaire for pacemaker patients to assess quality of life (QoL) available. The Aquarel questionnaire was developed as a disease-specific extension to the Short-Form-36 (SF-36). A cross-sectional study was carried out in 74 pacemaker patients to evaluate validity and reliability of this instrument. Items were selected and scales constructed based on factorial analysis. Internal consistency, content validity and test-retest reliability were moderate to excellent. Correlations with the SF-36 scales, pacing mode and functional tests were as hypothesized, demonstrating the individual value and distinctiveness of the Aquarel subscales. The results support the feasibility and usefulness of evaluating QoL in pacemaker patients when using Aquarel as an extension to the SF-36.

Quality-of-life in patients treated with atrioventricular synchronous pacing compared to rate modulated ventricular pacing: a long-term, double-blind, crossover study.

To investigate whether the preservation of atrioventricular (AV) synchronization matters for quality-of-life during pacemaker treatment we assessed 17 consecutive patients with high degree AV block and preserved sinus node function in a double-blind, long-term crossover study. A questionnaire with regard to cardiovascular symptoms, sleep disturbances, cognitive functioning, physical ability, social interaction, emotional functioning, and self-perceived health was completed after 2 months of atrial synchronous (DDD) and rate modulated ventricular pacing (VVI,R), respectively. A significant improvement in shortness of breath, dizziness and palpitations as well as an improvement of cognitive functioning was observed during DDD pacing. Nine patients preferred the DDD mode and three the VVI,R mode. The remaining five patients did not express any preference. The preference for the DDD mode was explained by a significant reduction of cardiovascular symptoms and an improved self-perceived health, physical ability, and psychological well-being during DDD pacing. All differences in quality-of-life parameters between the two modes of pacing favored the DDD mode and no adverse effects of this mode were found. Thus, the maintenance of AV synchrony adds further symptomatic relief compared to rate increase alone. The results indicate that DDD pacing is the preferred mode of pacing in patients with high degree AV block and preserved sinus node function.

The impact of pacemaker implantation on cognitive functioning in elderly patients.

OBJECTIVE: To describe and quantify the impact of pacemaker implantation on cognitive functioning in the elderly. DESIGN: Prospective case-control, non-randomized trial. Data were collected from clinical and family interviews and from a psychological test battery. SETTING: Pacemaker clinic in a tertiary care hospital. PARTICIPANTS: Nineteen elderly (65+ years) patients undergoing new or replacement pacemaker implantation for dysrhythmias and volunteer controls matched for age, sex, and short Mental Status Questionnaire test results, without dysrhythmia or intervention. MAIN OUTCOME MEASURES: Subjective and clinical impressions based on family interviews; results of psychological test battery before and 6-12 months after pacemaker implantation. RESULTS: Prior to pacemaker implantation, three patients met DSM-III criteria for dementia and two for delirium. Paced patients demonstrated deficiency in immediate memory, language, memory for less structured information, and learning of abstract materials. These deficits were due primarily to the poor performance of patients with complete heart block. Despite clinical and subjective impressions of improvement, there was no change in psychologic test performance subsequent to pacemaker implantation. CONCLUSIONS: Impaired cognitive functioning is not always clinically apparent but appears common in patients with cardiac dysrhythmias; it is not altered 6-12 months after pacemaker implantation.

Single-lead VDD pacing: excellence or expedience?

The interest in VDD pacemakers has been renewed by the introduction of single-pass leads, and continuing modifications and technical developments promise significant improvement. However, convincing long-term data confirming the reliability and the use of newer leads are not yet available. Compared with VVIR pacemakers VDD pacing has theoretical advantages over the VVIR mode, offering better hemodynamic and endocrine responses. However, its range of indications is narrow and rate adaptation is essential when sinus node chronotropic inadequacy is present or likely to occur. In addition, on certain occasions a VDD pacemaker may not maintain persistent atrial-synchronous pacing, thus necessitating the use of a DDD unit.