Transient Sinus Node Dysfunction Associated with Herpes Simplex Encephalitis.

Sinus arrest and inappropriate sinus bradycardia are sinus node dysfunction (SND), which cause loss of consciousness. Cardiac pacing is recommended in patients with symptoms, such as syncope or dizziness. Several conditions can induce these arrhythmias; however, whether or not intracranial infectious diseases, such as herpes simplex encephalitis (HSE), can cause secondary SND is unclear. We encountered a patient with sinus arrest and transient sinus bradycardia associated with HSE. Since cardiac pause was never monitored and the bradycardia improved after HSE treatment, HSE was suspected to be the cause of SND. Although the underlying mechanisms have not yet been completely elucidated, HSE may cause secondary SND.

Pericardial effusion caused by accidently placing a Micra transcatheter pacing system into the coronary sinus.

BACKGROUND: Leadless pacemaker has been acknowledged as a promising pacing strategy to prevent pocket and lead-related complications. Although rare, cardiac perforation remains a major safety concern for implantation of Micra transcatheter pacing system (TPS). CASE PRESENTATION: A 83-year-old female with low body mass index (18.9 kg m-2) on dual anti-platelet therapy, was indicated for Micra TPS implantation due to sinus arrest and paroxysmal atrial flutter. The patient developed mild pericardial effusion during the procedure since the delivery catheter was accidentally placed into the coronary sinus for several times. Cardiac perforation with moderate pericardial effusion and pericardial tamponade was detected 2 h post-procedure. The patient was treated with immediately pericardiocentesis and recovered without further invasive therapy. CONCLUSION: Pericardial effusion caused by accidently placing a delivery catheter into the coronary sinus is rare but should be carefully considered in Micra TPS implantation, especially for those with periprocedural anti-platelet therapy.

Very delayed sinus arrest during complete remission of diffuse large B-cell lymphoma invading right atrium.

Diffuse large B-cell lymphoma (DLBCL)-associated arrhythmias may be due to cardiac involvement or may be chemotherapy-induced. There have been no reports of significant arrhythmias with normal cardiac function occurring during the complete remission of DLBCL. A 57-year-old female, who had had no history of abnormal electrocardiograms (ECGs) in annual medical checkups, was admitted to our hospital because of low-grade fever, night sweats, and weight loss. On admission, ECG revealed a variable rhythm consisting of sinus beats and occasional escape beats. Computed tomography and 18F-fluorodeoxyglucose positron emission tomography and computed tomography (FDG-PET/CT) revealed two masses in the right atrium (RA) and the uterus. Total hysterectomy was performed, and pathological findings were consistent with diffuse large B-cell lymphoma (DLBCL). Chemotherapy (R-CHOP) was initiated. After two chemotherapy cycles, RA tumors disappeared, and bradyarrhythmia simultaneously converted to sinus rhythm without antiarrhythmic drug therapy. Six months after completion of chemotherapy, FDG-PET/CT revealed negative uptake in the RA and the uterus. The patient attained complete remission of DLBCL, but ECG showed bradycardia because of sinus arrest. Our case suggests that DLBCL-induced arrhythmia can occur even after its remission and should be monitored.

Mechanodefibrillator dissociation due to prolonged sinus arrest / Mecano disociación del desfibrilador debido a un paro sinusal prolongado

To the editor, Sinus arrest and cardiac arrest are two different terms which are often confused by many. This confusion often leads to inappropriate cardiopulmonary resuscitation (CPR) when patient is connected to defibrillator. Sinus arrest is defined as transient pause in Sino-atrial firing for more than 3 s1. When sinus arrest occurs, other latent pacemakers (atrial myocardium, cells nearby atrioventricular node, and His purkinje system) usually starts firing until Sino-atrial node recover. Sinus arrest can be prolonged till other pacemakers starts firing2. Cardiac arrest occurs when these latent pacemakers does not take up the job of alternate firing. Prolonged sinus arrest in a defibrillator may look like a cardiac arrest which might lead to unnecessary CPR. Here, we would like the put forward a new term “mechano - defibrillator dissociation” which occurs because of prolonged sinus arrest. We should be aware this, so that inappropriate CPR could be avoided. We, emergency physician also faced similar situation while resuscitating a patient because of mechano - defibrillator dissociation caused by prolonged sinus arrest/pseudo cardiac arrest. A 52-year-old male diabetic, hypertensive, and chronic alcoholic came to our emergency department (ED) with history of giddiness, syncope, and palpitation. On arrival to ED, patient was drowsy, diaphoretic, and hypotensive. Patient was connected to defibrillator which showed a heart rate of 35/min and saturation was 90% in room air. ECG showed complete heat block (CHB) and point of care echocardiography showed reduced ejection fraction.

Severe secondary hyperkalemia and arrhythmia from drug interactions between calcium-channel blocker and voriconazole: a case presentation.

BACKGROUND: Patients with kidney disease may have concurrent hypertension and infection. Dihydropyridine calcium-channel blockers (CCB) are the most popular class of antihypertensive drugs used in clinical settings and can be metabolized by cytochrome P450 isoenzyme 3A4 (CYP3A4). Voriconazole is a commonly used antifungal treatment and a CYP3A4-inhibitor. Insufficient attention to drug interactions from the concomitant use of CCB and voriconazole may result in serious adverse reactions. CASE PRESENTATION: Here, we report a patient with acute kidney injury on stable anti-neutrophil cytoplasm antibody associated vasculitis who developed hyperkalemia resulting in sinus arrest with junctional escape rhythm attributed to drug interactions of CCB with voriconazole. This is a very rarely reported case and may be an under-recognized complication. After continuous renal replacement therapy and changing the anti-hypertensive drugs, symptoms, and laboratory abnormalities of the patient fully recovered. CONCLUSIONS: This case warns us of severe consequences of drug interactions. Co-prescription of CYP3A4-inhibitors with calcium-channel blockers increases the risk of hypotension and acute kidney injury, which may further induce hyperkalemia and arrhythmia.

A rare case of late-onset ticagrelor-induced sinus arrest.

Ticagrelor is a potent reversible P2Y12 inhibitor with proven superiority over clopidogrel. Ticagrelor increases the tissue concentration of adenosine, thereby leading to bradyarrhythmia. This complication is reported to occur very early after initiating the drug. A randomized controlled trial reported that ticagrelor-induced pauses have an early onset without much clinical impact. However, our patient developed ticagrelor-induced hemodynamically significant sinus arrest 10 months after coronary artery stenting, which improved after stopping the drug. Ticagrelor should be considered as one of the uncommon reasons for late-onset sinus pause or bradyarrhythmia.

Aging-associated sinus arrest and sick sinus syndrome in adult zebrafish.

Because of its powerful genetics, the adult zebrafish has been increasingly used for studying cardiovascular diseases. Considering its heart rate of ~100 beats per minute at ambient temperature, which is very close to human, we assessed the use of this vertebrate animal for modeling heart rhythm disorders such as sinus arrest (SA) and sick sinus syndrome (SSS). We firstly optimized a protocol to measure electrocardiogram in adult zebrafish. We determined the location of the probes, implemented an open-chest microsurgery procedure, measured the effects of temperature, and determined appropriate anesthesia dose and time. We then proposed an PP interval of more than 1.5 seconds as an arbitrary criterion to define an SA episode in an adult fish at ambient temperature, based on comparison between the current definition of an SA episode in humans and our studies of candidate SA episodes in aged wild-type fish and Tg(SCN5A-D1275N) fish (a fish model for inherited SSS). With this criterion, a subpopulation of about 5% wild-type fish can be considered to have SA episodes, and this percentage significantly increases to about 25% in 3-year-old fish. In response to atropine, this subpopulation has both common SSS phenotypic traits that are shared with the Tg(SCN5A-D1275N) model, such as bradycardia; and unique SSS phenotypic traits, such as increased QRS/P ratio and chronotropic incompetence. In summary, this study defined baseline SA and SSS in adult zebrafish and underscored use of the zebrafish as an alternative model to study aging-associated SSS.

Syncope and Twitching at the Emergency Department.

BACKGROUND Anti-LGI1 encephalitis is a type of autoimmune limbic encephalitis. This case report elucidates features of anti-LGI1 limbic encephalitis, focusing on clinical findings and outcome as well as on rarely reported sinus arrest and its pathophysiology. CASE REPORT A 49-year-old female patient presented at the Emergency Department (ED) because of twitching and an acute confusional state. Initial neurological examination revealed cognitive disturbance with disorientation, inattention, and amnestic deficits. While in the ED, twitching of the right arm was observed and shortly thereafter she experienced a sinus arrest. A temporary cardiac pacemaker was implanted. Laboratory investigations demonstrated mild hyponatremia and positive LGI1-IgG antibodies in serum. An initial head MRI was unremarkable and electroencephalography showed epileptic seizure activity starting focally in the left hemisphere synchronous with the intermittent twitching of the right arm. A seizure-suppressant therapy with levetiracetam, valproate, and gabapentin was initiated, as well as an immunosuppressive pulse therapy with methylprednisolone followed by a tapering oral regimen of prednisolone. Within a few days, the seizures ceased. One month later, neurocognitive test results were back to normal. At 2 years, mild depressive symptoms and anxiety disorder were the main clinical problems, as well as episodic migraine-like headaches. CONCLUSIONS Repetitive focal dystonic seizures, confusion, amnestic deficits, sinus arrest, and mild-to-moderate hyponatremia are pathognomonic features of anti-LGI1 limbic encephalitis. Sinus arrest may occur because of a direct pathophysiological dysfunction of the structures involved in autonomic cardiac rhythm control or as an ictal or postictal phenomenon. Early diagnosis and initiation of immunosuppressive therapy are both of utmost importance for favorable clinical outcome.

Chinese Patent medicine to treat a 32-year-old man with sinus bradycardia and cardiac sinus arrests: A case report.

RATIONALE: Sinus bradycardia refers to a sinus heart rate <60 bpm. Cardiac sinus arrests refer to the omission of atrial activation caused by transient cessation of impulse generation at the sinoatrial node. Normally, drugs such as atropine, isoproterenol, dopamine, dobutamine, or epinephrine can be used for the acute treatment of bradycardia. Temporary pacing is used for treating severe symptomatic bradycardia due to a reversible cause. Permanent cardiac pacing is used for chronic therapy of bradycardia. However, for traditional Chinese medicine (TCM), benefiting qi and nourishing yin and activating blood circulation is the general principle in treatment and show remarkable curative effects. PATIENT CONCERNS: A 32-year-old man was found to have 1-degree atrioventricular block and sinus bradycardia during a physical examination. He reported suffering from palpitation and shortness of breath occasionally. An ambulatory electrocardiogram showed sinus arrhythmia, sinus bradycardia, and significant sinus arrhythmia. The minimum heart rate was 33 bpm (beats per minute). The number of sinus arrest was 42 and the maximum RR interval was 2216 ms. DIAGNOSES: The patient was diagnosed with bradyarrhythmia in Western medicine and "palpitation" in TCM. INTERVENTIONS: The patient was treated with methods of benefiting qi and nourishing yin and activating blood circulation along with warming yan for nearly 5 months. CPM (Chinese patent medicine) such as Yixinshu capsule, Bingdouling oral liquid, Zhenyuan capsule, Zhibaidihuang pills were used for treatment. At the same time, he was suggested to change his lifestyles including falling asleep before 10:00 PM and abandoning spicy diets. OUTCOMES: The symptoms of palpitation and shortness of breath disappeared. The minimum heart rate increased from 33 to 42 bpm and sinus arrests did not occur. The maximum RR interval decreased from 2216 to 1650 ms and the remarkable sinus arrhythmia had improved obviously. LESSONS: This case report shows that TCM can be an effective alternative therapy for sinus bradycardia and cardiac sinus arrests. CPM may have been a successful intervention in arrhythmias.

Transient sinus arrest due to sinus node artery thrombus after revascularisation of the left circumflex artery.

We present a case of sinus arrest and junctional escape rhythm from sinus node artery (SNA) thrombus in a 55-year-old man after revascularisation of right coronary and proximal circumflex arteries for infero-posterior wall ST-segement elevation myocardial infarction (STEMI). Sinus arrest from occlusion of the SNA is uncommon. The ensuing bradycardia may have haemodynamic consequences requiring temporary pacing but is almost always self-limited.

Continuous Positive Airway Pressure Therapy Improves Heterogeneity of R-R intervals in a Patient with Obstructive Sleep Apnea Syndrome.

Obstructive sleep apnea (OSA) is associated with the occurrence of various kinds of bradyarrhythmia and tachyarrhythmia. The activation of the autonomic nerve system is an important causative factor of the pathogenesis of the arrhythmia in OSA patients. Previous studies have shown that the R-R interval is an effective parameter for evaluating autonomic nerve activities. However, whether or not OSA can induce variations in the R-R interval and whether or not continuous positive airway pressure (CPAP) therapy can improve these variations in OSA patients are unclear. The present study explored whether or not CPAP therapy could improve the regularity of the R-R interval.

ECG de febrero de 2018 / ECG, February 2018

No disponible

A 1-year-old boy with long pauses caused by paroxysmal atrioventricular block and sinus arrest: Vagal reflex and effect of pacing.

Paroxysmal atrioventricular block (PAVB) is rare in children. A 1-year-old boy presented with PAVB and sinus arrest that resulted in refractory life-threatening symptomatic long pauses. Continuous heart rate variability analysis with high time resolution (wavelet analysis) revealed an abrupt increase in parasympathetic activity just before a long pause, which indicated a vagal reflex. Although a pacemaker is not always effective because of a concomitant vasodepressive response in such cases, the complete stabilization after pacemaker implantation in this case supports the necessity and usefulness of pacemaker implantation in patients with reflex-induced highly symptomatic bradycardia.

Acute Sinus Node Dysfunction after Atrial Ablation: Incidence, Risk Factors, and Management.

BACKGROUND: Many patients with atrial fibrillation (AF) or atrial flutter (Aflutter) have concomitant sinus node dysfunction (SND). Ablation may result in injury to the sinus node complex or its blood supply resulting in sinus arrest and need for temporary pacing. We sought to characterize patients who develop acute SND (ASND) during/immediately after AF/Aflutter ablation. METHODS: We performed a retrospective analysis of AF/Aflutter ablation patients between January 1, 2010 and February 28, 2015 to characterize those who required temporary pacemaker (TPM) implantation due to ASND (sinus arrest, sinus bradycardia <40 beats/min, or junctional rhythm with hemodynamic compromise) following atrial ablation. RESULTS: Of 2,151 patients, eight patients (<0.5%) with ASND manifesting as sinus arrest (n = 2), severe sinus bradycardia (n = 2), and junctional rhythm with hemodynamic compromise (n = 4) were identified (all male, age 66 ± 9.9 years, 4/8 [50%] persistent AF). AF ablation was performed in four, atypical Aflutter in one, and AF/Aflutter in three patients. The ablation set consisted of: pulmonary vein (PV) isolation (n = 6), roof line ablation (n = 6), mitral annulus-left inferior PV line ablation (n = 5), left atrial appendage-mitral annulus ablation (n = 1), cavotricuspid isthmus ablation (n = 5), and isolation or ablation near the superior vena cava (SVC, n = 4). Patients with peri-SVC ablation were more likely to develop ASND (P = 0.03). All patients received TPM; six received permanent pacemaker before discharge, performed 3.5 days postablation (range 2-6 days). At 3-month device interrogation, all patients were atrially paced >50%. CONCLUSION: ASND is a rare complication of atrial ablation. It may be more common when peri-SVC ablation is performed and may necessitate permanent pacemaker implantation.

Vagoglossopharyngeal Neuralgia Occurred Concomitantly with Ipsilateral Hemifacial Spasm and Versive Seizure-Like Movement: A First Case Report.

Vagoglossopharyngeal neuralgia (VGPN) is a very rare condition. VGPN with convulsive like attack is even rarer All of the cases had their head turned to the opposite side of facial pain. Hemifacial spasm occurring concurrently with VGPN has never been reported. Herein, we present the first case of VGPN that had ipsilateral hemifacial spasm and versive seizure-like movement to the same side of facial pain. We reported a 71-year-old man presenting with multiple episodes of intermittent sharp shooting pain arising on the right middle neck, followed by hemifacial spasm on right face. Then the patient became syncope while his head and gaze turned to the same side of the painful neck. Electrocardiography showed sinus arrest. Interictal Electroencephalography was normal. This patient initially responded to pregabalin for two weeks, then the symptoms became worse. Microvascular decompression and carbamazepine resulted in the complete remission of all symptoms after six months of follow-up. We could not explain the pathophysiology of unilateral versive seizure like movement.