Electrical injury is a serious public health problem. Heart is one of the most frequently affected organs. Electrical injury can cause life-threatening cardiac complications such as asystole, ventricular fibrillation, and myocardial rupture. In this case report, we present a 20-yr-old male patient with sick sinus syndrome that developed years after electrical injury.
Adult ; Atropine/diagnostic use ; Electric Injuries/complications* ; Electrocardiography ; Exercise Tolerance ; Human ; Male ; Pacemaker, Artificial ; Sick Sinus Syndrome/etiology* ; Sick Sinus Syndrome/physiopathology ; Sick Sinus Syndrome/therapy ; Sinoatrial Node/physiopathology ; Time Factors

Current permanent right ventricular and right atrial endocardial pacing leads are implanted utilizing a central lumen stylet. Right ventricular apex pacing initiates an abnormal asynchronous electrical activation pattern, which results in asynchronous ventricular contraction and relaxation. When pacing from right atrial appendage, the conduction time between two atria will be prolonged, which results in heterogeneity for both depolarization and repolarization. Six patients with Class I indication for permanent pacing were implanted with either single chamber or dual chamber pacemaker. The SelectSecure 3830 4-French (Fr) lumenless lead and the SelectSite C304 8.5-Fr steerable catheter-sheath (Medtronic Inc., USA) were used. Pre-selected pacing sites included inter-atrial septum and right ventricular outflow tract, which were defined by ECG and fluoroscopic criteria. All the implanting procedures were successful without complication. Testing results (mean atrial pacing threshold: 0.87 V; mean P wave amplitude: 2.28 mV; mean ventricular pacing threshold: 0.53V; mean R wave amplitude: 8.75 mV) were satisfactory. It is concluded that implantation of a 4-Fr lumenless pacing lead by using a streerable catheter-sheath to achieve inter-atrial septum or right ventricular outflow tract pacing is safe and feasible.
Cardiac Pacing, Artificial/*methods ; Electrodes, Implanted ; Equipment Safety ; Pacemaker, Artificial ; Prosthesis Implantation/methods ; Sick Sinus Syndrome/*therapy

This study aims to mine the regularity of traditional Chinese medicine(TCM) prescriptions for sick sinus syndrome(SSS) and provide a reference for clinical syndrome differentiation and treatment. The relevant papers were retrieved from CNKI, Wanfang, VIP, and SinoMed with the time interval from inception to January 31, 2023. The relevant information from qualified papers was extracted to establish a library. Lantern 5.0 and Rstudio were used to analyze the latent structure and association rules of TCMs with the frequency ≥3%, which combined with frequency descriptions, were used to explore the rules of TCM prescriptions for SSS. A total of 192 TCM prescriptions were included, involving 115 TCMs with the cumulative frequency of 1 816. High-frequency TCMs include Aconiti Lateralis Radix Praeparata, Ginseng Radix et Rhizoma, Glycyrrhizae Radix et Rhizoma, Astragali Radix, and Salviae Miltiorrhizae Radix et Rhizoma. The high-frequency medicines mainly had the effects of tonifying, releasing exterior with pungent-warm, and activating blood and resolving stasis. The analysis of the latent structure model yielded 13 hidden variables, 26 hidden classes, 8 comprehensive cluster models, and 21 core prescriptions. Accordingly, the common syndromes of SSS were inferred as heart-Yang Qi deficiency, heart-spleen Yang deficiency, heart-kidney Yang deficiency, Yang deficiency and blood stasis, both Qi and Yin deficiency and blood stasis, and Yin and Yang deficiency. The analysis of association rules predicted 30 strong association rules, among which Ginseng Radix et Rhizoma-Aconiti Lateralis Radix Praeparata had the highest support. SSS is a syndrome with Yang deficiency and Qi deficiency as the root causes and cold, phlegm, and stasis as the manifestations. The clinical treatment of SSS should focus on warming Yang and replenishing Qi, which should be supplemented with the therapies of activating blood and resolving stasis, warming interior and dissipating cold, or regulating Qi movement for resolving phlegm according to the patients' syndromes.
Humans ; Sick Sinus Syndrome/drug therapy* ; Yang Deficiency/drug therapy* ; Drugs, Chinese Herbal/pharmacology* ; Medicine, Chinese Traditional ; Prescriptions ; Rhizome/chemistry* ; Aconitum ; Panax

BACKGROUND: Sinus node dysfunction (SND) is caused not only by intrinsic sinus node disease, but also by the extrinsic factors. Among the extrinsic factors, autonomic imbalance is most common. Symptomatic SND usually requires permanent pacemaker therapy. However, the clinical characteristics and patient response to medical therapy for hypervagotonic SND have not been properly clarified. MATERIALS AND METHODS: Thirty two patients (14 men, 18 women, 51 +/- 14 years) with hypervagotonic SND were included in this study, but those patients who had taken calcium antagonists, beta-blockers or other antiarrhythmic drugs were excluded. Hypervagotonic SND was diagnosed if the abnormal electrophysiologic properties of the sinus node were normalized after the administration of atropine (0.04 mg/kg). RESULTS: The presenting arrhythmias were 16 cases of sinus bradycardia (50.0%), 12 of sinus pause (37.5%), 3 of sinoatrial block (9.4%) and 1 of tachy-bradycardia (3.1%). Nine (28.1%) patients had hypertension, 7 (21.9%) smoked, 2 (6.3%) had diabetes mellitus, and 1 (3.1%) had hypercholesterolemia. Among the patients, 3 had no remarkable symptoms, 13 had dizziness, 7 had syncope, 3 had weakness and 6 had shortness of breath. Twenty five (78.1%) patients were treated with theophylline, 1 patient with tachy-bradycardia syndrome was treated with digoxin and propafenone, and 6 (18.8%) were treated with no medication. During the 43 +/- 28 month follow-up, 25 patients remained asymptomatic, but 6 who took no medication developed mild dizziness. One patient needed permanent pacemaker implantation owing to recurrent syncope despite of theophylline treatment. CONCLUSION: These results show that hypervagotonic SND has a benign course and most of the patients can be managed safely without implanting a pacemaker. (Ed note: I like the abstract. It is short and direct, as it should be.)
Dizziness/etiology ; Dyspnea/etiology ; Female ; Humans ; Male ; Middle Aged ; Muscle Weakness/etiology ; Sick Sinus Syndrome/*complications/drug therapy ; Syncope/etiology ; Theophylline/therapeutic use ; Vasodilator Agents/therapeutic use

OBJECTIVETo construct plasmid expressing pacemaker gene pIRES2-EGFP-HCN2 and study its effects in transfected atrial myocytes in vitro and in canine model of sick sinus syndrome (SSS).

METHODSmHCN2 gene was isolated from PTR plasmids and cloned into eukaryotic expression plasmid pIRES2-EGFP. Recombinant plasmids pIRES2-EGFP-HCN2 was transfected with by electroporation into neonatal atrial cardiomyocytes or injected to the sinoatrial (SA) region of canines with SSS induced by catheter and chemical ablation. pIRES2-EGFP-HCN2 expression was detected under fluorescence microscope and confirmed by reverse transcription-polymerase chain reaction (RT-PCR). Spontaneous beating rate in atrial cardiomyocytes was detected with light microscope.

RESULTSEGFP expression was seen in transfected atrial cardiomyocytes 24 to 48 hours after transfection and the spontaneous beating rate was significantly increased than that in non-transfected atrial cardiomyocytes [(180 +/- 11) bpm vs (140 +/- 14) bpm, P < 0.05]. Heart rate was significantly increased 24 hours post recombinant plasmids pIRES2-EGFP-HCN2 injection compared to saline injection in canines with SSS [(150 +/- 13) bpm vs (105 +/- 17) bpm, P < 0.05]. Green fluorescence was also detected in frozen SA tissue sections of canines injected with recombinant plasmids pIRES2-EGFP-HCN2 and the production amplified by RT-PCR was about 300 bp which is consistent with mHCN2 gene fragment.

CONCLUSIONThe recombinant eukaryotic expression plasmid pIRES2-EGFP-HCN2 can improve pacing function in atrial myocytes and in canine model of SSS.

Animals ; Disease Models, Animal ; Dogs ; Gene Expression ; Gene Transfer Techniques ; Genetic Therapy ; Genetic Vectors ; Hyperpolarization-Activated Cyclic Nucleotide-Gated Channels ; In Vitro Techniques ; Ion Channels ; genetics ; Myocytes, Cardiac ; metabolism ; Plasmids ; Sick Sinus Syndrome ; therapy

OBJECTIVETo explore the effect of Qiangxin Fumai Granule (QFG, a Chinese herbal preparation for treatment of sick sinus syndrome) contained serum (QFG-S) on sinoatrial node cells during Ca2+ overloading induced by simulated ischemia/reperfusion.

METHODSModel Ca2+ overloading cells were established on sinoatrial node cells from newborn rats, with deprivation of oxygen and glucose to simulate ischemia and with restoration of them to simulate reperfusion. Cells were divided into 5 groups, those in the normal and model control groups were modeled directly and those in the treated groups were pre-cultured with UMEM containing respective medicines in aerobic environment for 30 mm before ischemia/reperfusion simulation. Cell Ca2+ concentration and morphology were observed by invert microscope and fluorescence spectrophotometer.

RESULTSMost cells in the model control group revealed cell edema and deformation, even abscission. By HE staining, many minimal vacuole appeared in cytoplasm, with crumpled nuclear membrane, partially damaged. While cells in the QFG-S treated group, either high-dose or low-dose, were attached grew well, with basically smooth and complete membrane and nuclear membrane, normal in size and shape. The intracellular Ca2+ concentration raised significantly after modeling, but it was much lower in the QFG-S treated group than in the model control group (P < 0.01) and it was not changed obviously in the atropine treated group.

CONCLUSIONQFG-S could diminish the injury of cell induced by simulated ischemia/reperfusion, the acting mechanism for treatment of sick sinus syndrome might be related to its effect in relieving Ca2+ overloading and thus protecting cells from injury.

Animals ; Calcium ; metabolism ; Disease Models, Animal ; Drugs, Chinese Herbal ; administration & dosage ; Female ; Humans ; Ischemia ; drug therapy ; metabolism ; Male ; Rats ; Rats, Wistar ; Serum ; chemistry ; Sick Sinus Syndrome ; drug therapy ; metabolism ; Sinoatrial Node ; drug effects ; metabolism

OBJECTIVE: To evaluate the efficacy of atrial pacing to increase the heart rate during sleep in elderly patients with sleep apnea syndrome. METHODS: Sixteen elderly patients with central type or obstructive type sleep apnea received permanent atrial-synchronous ventricular pacemakers for symptomatic sinus bradycardia were analysed in this study. All patients received polysomnographic evaluations for 3 consecutive nights. All patients were evaluated at the base-line, and then were randomly divided into 2 groups at the first night. In the following 2 nights, one group was monitored in spontaneous rhythm model and the other in dual-chamber pacing model with atrial overdrive (increasing by 15 beats per minute on the basic rate of the mean nocturnal sinus), and then the two groups were switched at the third night. The total duration and number of episodes of sleep apnea or hypopnea were analyzed, and compared between the two models. RESULTS: The mean 24 h sinus rate in the spontaneous rhythm mode was 55+/-9 beats per minute at the base line, as compared in the 72+/-4 beats per minute in the atrial overdrive pacing model. There was statistic significant difference between the 2 models (P<0.05). There was no difference in the total duration of sleep between spontaneous rhythm model and atrial overdrive pacing model [(322+/-48) minutes vs (330+/-52) minutes, P>0.05 ]. The hypopnea index reduced from 9+/-3 in the spontaneous rhythm model to 3+/-3 in the atrial overdrive pacing model (P<0.01). The index of apnea and hypopnea was 28+/-21 in the spontaneous rhythm model, as compared with 10+/-13 in the atrial overdrive pacing model (P<0.01). CONCLUSION Atrial overdrive pacing can significantly reduce the number of episodes of central type or obstructive type sleep apnea, but doesn't decrease the total sleep time in elderly patients with sleep apnea syndrome.
Aged ; Aged, 80 and over ; Cardiac Pacing, Artificial ; methods ; Female ; Heart Atria ; Heart Rate ; Humans ; Male ; Middle Aged ; Pacemaker, Artificial ; Polysomnography ; Sick Sinus Syndrome ; complications ; therapy ; Sleep ; physiology ; Sleep Apnea Syndromes ; complications ; therapy

The clinical data for a patient with sick sinus syndrome was retrospectively analyzed. The patient was treated because of his heart palpitations and the increased chest pain. The patient admitted to the hospital under consideration for the left atrial tumor dependent on the echocardiography findings. After the CT scan and the dynamic ECG examination, the patient successfully underwent the left atrial tumor resection, atrial septal repair and cardiac pacing lead installation. The postoperative pathological diagnosis showed that the infective endocarditis and left atrial thrombus in left atrium was cured. The patient was discharged after postoperative anti-inflammatory therapy. By analyzing the reasons for misdignosis before or during surgery, the possible mechanisms for left atrial subendocardial thrombus have been found. This study suggests that it is necessary to combine imaging diagnosis and clinical observations to distinguish tumor from excrescence.
Anti-Inflammatory Agents ; therapeutic use ; Arrhythmias, Cardiac ; etiology ; surgery ; Atrial Septum ; surgery ; Computed Tomography Angiography ; Diagnosis, Differential ; Diagnostic Errors ; Echocardiography ; Endocarditis ; diagnosis ; therapy ; Heart Atria ; diagnostic imaging ; surgery ; Heart Diseases ; etiology ; surgery ; Heart Neoplasms ; complications ; diagnostic imaging ; surgery ; Humans ; Male ; Pacemaker, Artificial ; Retrospective Studies ; Sick Sinus Syndrome ; etiology ; surgery ; Thrombosis ; etiology ; surgery