- Tying Ourselves in Knots to Avoid Ventricular Pacing in Sick Sinus Syndrome: Does it Matter? [Editorial]
- JCJACC Clin Electrophysiol 2017; 3(5):491-493
- Sinus Standstill in a Patient after Intracoronary Papaverine Administration for a Coronary Fractional Flow Reserve. [Journal Article]
- IHInt Heart J 2018 Apr 20
- A 78-year-old woman had paroxysmal atrial fibrillation and effort angina. Two months before she was admitted for a coronary angiography, she had been feeling dizzy. A Holter 24-hour electrocardiograp...
A 78-year-old woman had paroxysmal atrial fibrillation and effort angina. Two months before she was admitted for a coronary angiography, she had been feeling dizzy. A Holter 24-hour electrocardiography monitor exhibited an asymptomatic episode of 2.9 seconds of RR interval. She underwent a coronary angiography, which showed intermediate stenosis in the left descending artery. Fractional flow reserve (FFR) measurement using intracoronary papaverine administration was performed. After intracoronary papaverine (12 mg) administration, pause of 4 seconds led to polymorphic ventricular tachycardia (VT), although the VT terminated spontaneously. Premature ventricular beat occurred and led to sustained polymorphic VT. In cardiac electrophysiology study, pacing from the right atrium showed that the maximum sinus node recovery time (SRT) was 910 ms. After procainamide (10 mg/kg) administration, the maximum SRT was 16.3 seconds with some junctional escapes. After intravenous papaverine administration, there was a slight change. Intracoronary papaverine administration induced about 9-seconds pause with some junctional escapes. We conclude that intracoronary papaverine administration reveals potential sinus node dysfunction. The patient has been asymptomatic since the implantation of the pacemaker. Patients with suspicious sinus dysfunction should be careful.
- Severe brady-arrhythmias in systemic lupus erythematosus: prevalence, etiology and associated factors. [Journal Article]
- LLupus 2018 Jan 01; :961203318770526
- Background Severe brady-arrhythmias, requiring a permanent pacemaker (PPM), have been sparsely reported in systemic lupus erythematosus (SLE). The aim of this study was to describe the characteristic...
Background Severe brady-arrhythmias, requiring a permanent pacemaker (PPM), have been sparsely reported in systemic lupus erythematosus (SLE). The aim of this study was to describe the characteristics of such arrhythmias in a defined lupus cohort. Patients and methods The database of the Toronto Lupus Clinic ( n = 1366) was searched for patients who received a PPM. Demographic, clinical, immunological and therapeutic variables along with electrocardiographic (ECG) and echocardiographic findings (based on the last available test prior to PPM) were analyzed. Patients with a PPM (cases) were compared with age-, sex- and disease duration-matched patients without a PPM (controls). Analysis was performed with SAS 9.0; p < 0.05 was considered significant. Results Eighteen patients were identified, 13 (0.95%) with complete atrioventricular block and 5 (0.37%) with sick sinus syndrome. Disease duration at PPM implantation was 22 ± 12 years. Compared to controls, cases had more frequently coronary artery disease, hypertension, dyslipidemia and longer antimalarial (AM) treatment duration. The prevalence of first-degree atrioventricular block, right bundle branch block, left anterior fascicular block and septal hypertrophy was also higher. AM treatment was significantly associated with brady-arrhythmias (OR = 1.128, 95% CI = 1.003-1.267, p = 0.044). Nine patients had prior heart disease and one received a PPM two years after renal transplantation. Eight patients did not have any potential risk factors; prolonged AM therapy (mean 22 years) might have been the cause. Conclusions Apart from known causes, prolonged AM treatment may be associated with severe brady-arrhythmias in SLE. Certain ECG and echocardiographic characteristics may represent indicators of an ongoing damage in the conduction system.
- MECP2 mutation in a boy with severe apnea and sick sinus syndrome. [Journal Article]
- BDBrain Dev 2018 Apr 06
- Rett syndrome is a neurodevelopmental disorder caused by mutations in the MECP2 gene, which encodes methyl-CpG-binding protein 2 (MECP2). It almost exclusively affects the female sex and is considere...
Rett syndrome is a neurodevelopmental disorder caused by mutations in the MECP2 gene, which encodes methyl-CpG-binding protein 2 (MECP2). It almost exclusively affects the female sex and is considered lethal in the male sex. However, an increasing number of male patients with MECP2 mutations have been reported, including patients who suddenly died of unknown causes. We report a case of MECP2 mutation in a male patient who exhibited neonatal encephalopathy. He developed severe apnea, epilepsy, and psychomotor developmental delay and died suddenly of sick sinus syndrome at 17 months of age. Severe bradycardia had been noticed since 16 months of age. His older brother followed a similar clinical course and died at 30 months of age. The brother had also experienced severe bradycardia. This familial case might help to clarify the causes of sudden death in cases of MECP2 mutations.
- Acute Inferior Wall ST Segment Elevation Myocardial Infarction Caused Atrial Lead Dysfunction Reversed by Primary Percutaneous Coronary Intervention. [Journal Article]
- IHInt Heart J 2018 Apr 06
- The mechanism of atrial lead dysfunction varies in patients receiving pacemaker implantation and this needs to be investigated, especially when the causes are reversible. We report and discuss a 76-y...
The mechanism of atrial lead dysfunction varies in patients receiving pacemaker implantation and this needs to be investigated, especially when the causes are reversible. We report and discuss a 76-year-old female who had atrial lead dysfunction caused by acute myocardial infarction and who was recovered after primary percutaneous coronary intervention. The sequential electrocardiographic changes were demonstrated and the possible mechanisms were discussed.
- A rare missense mutation in MYH6 associates with non-syndromic coarctation of the aorta. [Journal Article]
- EHEur Heart J 2018 Mar 24
- CONCLUSIONS: Through a population approach, we found that a rare missense mutation p.Arg721Trp in the sarcomere gene MYH6 has a strong effect on the risk of CoA and explains a substantial fraction of the Icelanders with CoA. This is the first mutation associated with non-familial or sporadic form of CoA at a population level. The p.Arg721Trp in MYH6 causes a cardiac syndrome with highly variable expressivity and emphasizes the importance of sarcomere integrity for cardiac development and function.
- Outcomes of the Warden procedure for partial anomalous pulmonary venous drainage in children. [Journal Article]
- ICInteract Cardiovasc Thorac Surg 2018 Mar 23
- CONCLUSIONS: The Warden procedure for repair of PAPVD to the SVC can be performed with no operative mortality or permanent pacemaker requirement. Mid-term outcomes are excellent with a low occurrence of SVC obstruction.
- Heart rate reduction decreases central blood pressure in sick sinus syndrome patients with a permanent cardiac pacemaker. [Journal Article]
- JHJ Hum Hypertens 2018 Mar 27
- Increased resting heart rate (HR) contributes to higher cardiovascular mortality and morbidity in the healthy as well as in people with cardiovascular diseases, possibly due to elevated blood pressur...
Increased resting heart rate (HR) contributes to higher cardiovascular mortality and morbidity in the healthy as well as in people with cardiovascular diseases, possibly due to elevated blood pressure (BP) among other mechanisms. Data on the relationship between HR and central (aortic) BP remains controversial, however, and concerning β-blockers, it has been proposed that pharmacological HR lowering is associated with augmentation of central BP. We aimed to study the role of pharmacologically unaffected HR on central BP indices in sick sinus syndrome patients with a permanent cardiac pacemaker in the HR range from 40 to 90 bpm. We included 27 subjects (mean age 65.8 ± 9.5 years, 12 men) with a dual-chamber pacemaker implanted due to sick sinus syndrome. We determined central hemodynamic indices noninvasively during an atrial pacing mode at low (40 bpm), middle (60 bpm), and high (90 bpm) HR levels with an oscillometric cuff-based device (Sphygmocor XCEL). There was no difference in central systolic BP at the middle versus the high HR level (mean 121.2 ± 13.0 and 121.2 ± 12.1 mmHg, respectively, P = 0.9), but at the low HR level, it was significantly lower than at the middle HR level (mean 117.2 ± 13.1 and 121.2 ± 13.0 mmHg, P < 0.01). Our acute study provides evidence to suggest that at a HR of <60 bpm, sick sinus syndrome patients may have a lower central BP than at a higher HR, despite the proposed augmenting effects of low HR on central BP.
- Genetic analysis of sick sinus syndrome in a family harboring compound CACNA1C and TTN mutations. [Journal Article]
- MMMol Med Rep 2018; 17(5):7073-7080
- Sick sinus syndrome (SSS) is a sinus node dysfunction characterized by severe sinus bradycardia. SSS results in insufficient blood supply to the brain, heart, kidneys, and other organs and is associa...
Sick sinus syndrome (SSS) is a sinus node dysfunction characterized by severe sinus bradycardia. SSS results in insufficient blood supply to the brain, heart, kidneys, and other organs and is associated with the increased risk of sudden cardiac death. Bradyarrhythmia appears in the absence of any associated cardiac pathology and displays a genetic legacy. The present study identified a family with primary manifestation of sinus bradycardia (five individuals) along with early repolarization (four individuals) and atrial fibrillation (one individual). Targeted exome sequencing was used to screen exons and adjacent splice sites of 61 inherited arrhythmia‑associated genes, to detect pathogenic genes and variant sites in the proband. Family members were sequenced by Sanger sequencing and protein functions predicted by Polyphen‑2 software. A total of three rare variants were identified in the family, including two missense variants in calcium voltage‑gated channel subunit alpha1 C (CACNA1C) (gi:193788541, NM_001129843), c.1786G>A (p.V596M) and c.5344G>A (p.A1782T), and one missense variant in titin (TTN) c.49415G>A (p.R16472H) (gi:291045222, NM_003319). The variants p.V596M and p.R16472H were predicted to be deleterious and resulted in alterations in the amino acid type and sequence of the polypeptide chain, which may partially or completely inactivate the encoded protein. The comparison of literature, gene database, and pedigree phenotype analysis suggests that p.V596M or p.R16472H variants are pathogenic. The complex overlapping variants at three loci lead to a more severe phenotype in the proband, and may increase the susceptibility of individuals to atrial fibrillation. The simultaneous occurrence of V596M and R16472H may increase the severity of early repolarization. Various family members may have carried heterozygous mutants of p.A1782T and p.R16472H due to genetic heterogeneity, however did not exhibit clinical signs of cardiac electrophysiological alterations, potentially attributable to the low vagal tone. To the best of the author's knowledge, this is the first study to suggest the involvement of the novel missense CACNA1C c.1786G>A and TTN c.49415G>A variants in the inheritance of symptomatic bradycardia and development of SSS.
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- A case ofBrucella melitensisendocarditis in a patient with cardiovascular implantable electronic device. [Journal Article]
- IDInfect Drug Resist 2018; 11:387-390
- CONCLUSIONS: In all published studies onBrucellainfective endocarditis with a cardiovascular implantable device, the recommendation was for device removal and extended treatment with doxycycline combined with rifampin and/or trimethoprim-sulfamethoxazole, plus parenteral aminoglycosides for the first 3 weeks. There have been two cases in the literature that have studied CIED infected with brucellosis where an attempt was made to retain the device. In both cases, relapse occurred upon discontinuation of treatment. It is not clear whether lifelong antibiotic suppression treatment would prevent relapse.