[Sinus node disease and atrio-ventricular disorders in pregnant women. When temporary or permanent pacing is necessary?]. / Choroba wezla zatokowego i zaburzenia przewodzenia przedsionkowo komorowego u kobiet w ciazy. Czy i kiedy zabezpieczac czasowa lub stala stymulacja?

Sinus node disease and atrioventricularis disorders are very rarely observed in women during pregnancy. Bradyarrhythmia in pregnant women is divided into mild bradycardia connected with pressure on venous cava inferior by growing fetus, new detected AV disorders and existing before pregnancy: AV Ill degree block congenital or after surgery, sinus node disease and channelopathies. Management in bradyarrhythmia in pregnancy is very difficult, despite guidelines. Whenever possible problem should be resolved before pregnancy. When symptomatic AV III degree block with wide QRS complex escape rhythm is observed--the permanent pacing should be considered with echocardiography or electro-anatomical system using. Another option is novel temporary, prolonged pacing.

Correlating hemodynamic magnetic resonance imaging with high-field intracranial vessel wall imaging in stroke.

Vessel wall magnetic resonance imaging at ultra-high field (7 Tesla) can be used to visualize vascular lesions noninvasively and holds potential for improving stroke-risk assessment in patients with ischemic cerebrovascular disease. We present the first multi-modal comparison of such high-field vessel wall imaging with more conventional (i) 3 Tesla hemodynamic magnetic resonance imaging and (ii) digital subtraction angiography in a 69-year-old male with a left temporal ischemic infarct.

The symptom complex of familial sinus node dysfunction and myocardial noncompaction is associated with mutations in the HCN4 channel.

BACKGROUND: Inherited arrhythmias were originally considered isolated electrical defects. There is growing evidence that ion channel dysfunction also contributes to myocardial disorders, but genetic overlap has not been reported for sinus node dysfunction (SND) and noncompaction cardiomyopathy (NCCM). OBJECTIVES: The study sought to investigate a familial electromechanical disorder characterized by SND and NCCM, and to identify the underlying genetic basis. METHODS: The index family and a cohort of unrelated probands with sinus bradycardia were examined by electrocardiography, Holter recording, exercise stress test, echocardiography, and/or cardiac magnetic resonance imaging. Targeted next-generation and direct sequencing were used for candidate gene analysis and mutation scanning. Ion channels were expressed in HEK293 cells and studied using patch-clamp recordings. RESULTS: SND and biventricular NCCM were diagnosed in multiple members of a German family. Segregation analysis suggested autosomal-dominant inheritance of the combined phenotype. When looking for potentially disease-causing gene variants with cosegregation, a novel hyperpolarization-activated cyclic nucleotide channel 4 (HCN4)-G482R mutation and a common cysteine and glycine-rich protein 3 (CSRP3)-W4R variant were identified. HCN4-G482R is located in the highly conserved channel pore domain. Mutant subunits were nonfunctional and exerted dominant-negative effects on wild-type current. CSRP3-W4R has previously been linked to dilated and hypertrophic cardiomyopathy, but was also found in healthy subjects. Moreover, different truncation (695X) and missense (P883R) HCN4 mutations segregated with a similar combined phenotype in an additional, unrelated family and a single unrelated proband respectively, which both lacked CSRP3-W4R. CONCLUSIONS: The symptom complex of SND and NCCM is associated with heritable HCN4 defects. The NCCM phenotype may be aggravated by a common CSRP3 variant in one of the families.

Left atrial responses to acute right ventricular apical pacing in patients with sick sinus syndrome.

Chronic right ventricular apical (RVA) pacing can lead to an increased risk of heart failure and atrial fibrillation, but the acute effects of RVA pacing on left atrial (LA) function are not well known. Twenty-four patients with sick sinus syndrome and intact intrinsic atrioventricular conduction were included. All patients received dual-chamber pacemaker implants with the atrial lead in the right atrial appendage and the ventricular lead in the right ventricular (RV) apex. Transthoracic standard and strain echocardiography (measured by tissue Doppler imaging and speckle tracking image) were performed to identify functional changes in the left ventricle (LV) and LA before and after 1 hour of RVA pacing. The LA volume index did not change after pacing; however, the ratio of peak early diastolic mitral flow velocity (E) to peak early diastolic mitral annular velocity (Ea) was significantly increased and peak systolic LA strain (Sm), mean peak systolic LA strain rate (SmSR), peak early diastolic LA strain rate (EmSR), and peak late diastolic LA strain rate (AmSR) were significantly reduced after RV pacing. LV dyssynchrony, induced by RV pacing, had a significant correlation with E/Ea, Sm, and SmSR after pacing. E/Ea also had a negative correlation with Sm and SmSR after pacing. Multivariate regression analysis identified LV dyssynchrony and E/Ea as important factors that affect Sm, SmSR, EmSR, and AmSR after acute RVA pacing. Acute RVA pacing results in LA functional change and LV dyssynchrony and higher LV filling pressures reflected by E/Ea are important causes of LA dysfunction after acute RVA pacing.

Promoter polymorphism G-6A, which modulates angiotensinogen gene expression, is associated with non-familial sick sinus syndrome.

BACKGROUND: It is well known that familial sick sinus syndrome (SSS) is caused by functional alterations of ion channels and gap junction. Limited information is available on the mechanism of age-related non-familial SSS. Although evidence shows a close link between arrhythmia and the renin-angiotensin system (RAS), it remains to be determined whether the RAS is involved in the pathogenesis of non-familial SSS. METHODS: In this study, 113 patients with documented non-familial SSS and 125 controls were screened for angiotensinogen (AGT) and gap junction protein-connexin 40 (Cx40) promoter polymorphisms by gene sequencing, followed by an association study. A luciferase assay was used to determine the transcriptional activity of the promoter polymorphism. The interaction between nuclear factors and the promoter polymorphism was characterized by an electrophoretic mobility shift assay (EMSA). RESULTS: Association study showed the Cx40 -44/+71 polymorphisms are not associated with non-familial SSS; however, it indicated that four polymorphic sites at positions -6, -20, -152, and -217 in the AGT promoter are linked to non-familial SSS. Compared to controls, SSS patients had a lower frequency of the G-6A AA genotype (OR 2.88, 95% CI 1.58-5.22, P = 0.001) and a higher frequency of the G allele at -6 position (OR 2.65, 95% CI 1.54-4.57, P = 0.0003). EMSA and luciferase assays confirmed that nucleotide G at position -6 modulates the binding affinity with nuclear factors and yields a lower transcriptional activity than nucleotide A (P<0.01). CONCLUSION: G-6A polymorphism, which modulates the transcriptional activity of the AGT promoter, may contribute to non-familial SSS susceptibility.

Rhythm and conduction disturbances at midterm follow-up after the ross procedure in infants, children, and young adults.

BACKGROUND: To our knowledge, late electrophysiologic outcomes after the Ross procedure have not been described. The purpose of this study was to assess rhythm and conduction disturbances at midterm follow-up after the Ross procedure. METHODS: A cross-sectional analysis of Ross procedure survivors (January 1, 1995 to December 31, 2005) followed at our institution was performed, including resting and 24-hour ambulatory electrocardiography (Holter monitoring). Rhythm and conduction disturbances were described, and predictors of arrhythmia were identified. RESULTS: Of 64 eligible patients, 47 (71%) participated. Median age at surgery was 8.7 years (age range, 34 days to 34 years). Twenty-five patients (53%) had isolated aortic valve disease and 22 (47%) had complex left-sided heart disease. At median follow-up of 8.9 years (range, 2.6-11.1 years), 46 patients (98%) exhibited sinus rhythm. Sinus node dysfunction (SND), defined as a pause of 2 seconds or longer or bradycardia for age, was present in 7 patients (15%). Complete heart block requiring a pacemaker occurred in 2 patients (4%). Ventricular tachycardia (VT) was present in 7 patients (15%), including nonsustained VT in 5 patients on Holter monitoring, and sustained VT in 2 patients requiring defibrillator placement. In multivariate analysis, concurrent arch repair at the time of the Ross operation (p = 0.04), longer cross-clamp time at the time of Ross operation (p = 0.04), and right ventricular outflow tract obstruction on follow-up echocardiogram (p = 0.03) were associated with SND. Longer cross-clamp time (p = 0.03) was also associated with VT, along with older age at surgery (p = 0.06 for trend). CONCLUSIONS: At midterm follow-up after the Ross procedure, rhythm and conduction disturbances occur in one third of patients, including SND in 15%, atrioventricular block in 4%, and VT in 15%. Routine surveillance for late arrhythmias after the Ross procedure is warranted.

Remarkable thickening of right atrial wall in subjects with cardiac amyloidosis complicated with sick sinus syndrome.

We observed a 63-year old male with cardiac amyloidosis who presented with the clinical symptoms of sick sinus syndrome and dyspnea and abnormal thickening of the right atrial wall, which extended to the junction of the superior vena cava. This may explain the relationship of abnormal thickening of the right atrium which extends to the junction of the superior vena cava and right atrium with amyloid deposits in the sinus node and occurrence of sick sinus syndrome.

Familial isolated noncompaction of the left ventricular myocardium.

Noncompaction of the ventricular myocardium (sometimes referred to as 'spongy myocardium') is believed to represent an arrest in endomyocardial morphogenesis. The gross anatomical appearance is characterized by numerous excessively prominent trabeculations and deep intertrabecular recesses. Distinct morphological features can be diagnosed on two-dimensional echocardiography. We present here a family of isolated noncompaction of the left ventricular myocardium, in which 5 affected individuals suggested the presence of some genetic abnormalities in this disorder.

Cardiac anaesthesia in a patient with myotonic dystrophy.

We describe a patient with myotonic dystrophy who required open-heart surgery for an atrial septal defect. He also had a sick sinus syndrome and an abnormal myocardium on histological examination. Anaesthesia using fentanyl, droperidol, nitrous oxide and a low concentration of enflurane was uneventful. Atelectasis of the left lung developed on the first postoperative day after removal of the tracheal tube. This was successfully treated by fibreoptic bronchoscopy.