No abstract available.
Seizures* ; Sick Sinus Syndrome* ; Syncope

A 70-year-old woman developed sick sinus syndrome associated with thyrotoxicosis. Initial T3 was above 800ng/dl and TSH was below 0.05IU/ml. But sinus node dysfunction was resolved upon achieving a euthyroid state. This clinical course suggest that transient reversible sinus node dysfunction could be developed due to thyrotoxicosis.
Aged ; Female ; Humans ; Sick Sinus Syndrome* ; Thyrotoxicosis*

Pacemaker-mediated tachycardia(PMT) is a circus movement tachycardia that can occur in patients with dual chamber pacemaker with atrial sensing(VDD or DDD), when a ventricular depolarization, either spontaneous or paced, causes retrograde activation of the atrium. Recently, a number of pacemaker manufactures have incorporated in their devices a variety of relatively complex algorithms to prevent PMT. Despite these measures, PMT may still occur because of inappropriate programming or unpredictable variations of ventriculoatrial conduction. We report one case of PMT in a 78-year-old male who received DDD type pacemaker due to sick sinus syndrome. In this case, PMT was disappeared after reprogramming parameters of pacemaker and the application of PMT protection algorithm.
Aged ; Dichlorodiphenyldichloroethane ; Humans ; Male ; Sick Sinus Syndrome ; Tachycardia*

Symptomatic sinus bradycardia in adults with systemic lupus erythematosus (SLE) is rare. Here, we report a case of severe sinus bradycardia requiring temporary cardiac pacing in a SLE patient successfully treated using methylprednisolone pulse therapy.
Adult ; Bradycardia ; Humans ; Lupus Erythematosus, Systemic ; Methylprednisolone ; Sick Sinus Syndrome

Persistent left superior vena cava is a rare congenital anomaly resulting from the failure of the left cardinal vein to degenerate in utero. This anomaly was discovered in 0.3% of large autopsy examinations. Its most relevant clinical implication is the association with cardiac impulse formation and conduction problems. In the case of DDD pacemaker implantation for this anomaly, skillful manual stylet shaping is required or an active fixation device, for example a screw device for stable positioning of pacemaker leads, is needed. We experienced a case of sick sinus syndrome in a patient with persistent left superior and absent right superior vena cava in 72-year-old man. We successfully implanted a DDD type pacemaker through the left superior vena cava via coronary sinus. This is the first Korean report of a successfully implanted permanent pacemaker in a patient with persistent left superior and absent right superior vena cava.
Aged ; Autopsy ; Coronary Sinus ; Dichlorodiphenyldichloroethane* ; Humans ; Sick Sinus Syndrome ; Veins ; Vena Cava, Superior*

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

Pacemaker-mediated tachycardia (PMT) is a well-known complication of dual-chamber pacemaker with atrioventricular sensing and pacing (DDD) or atrial synchronous, ventricular demand pacemaker (VDD). PMT usually starts with sensing a retrograde P waves linked to ventricular extrasystole with retrograde ventriculoatrial conduction and forms reentrant or circus movement tachycardia with the pacemaker itself as an antegrade limb and the conducting tissue of the heart as a retrograde limb. Recently, a number of pacemaker manufactures have incorporated in their devices a variety of relatively complex algorithms to prevent PMT. Despite these measures, PMT may still occur because of inappropriate programming or unpredictable variations of ventri-culoatrial conduction. We report two cases of PMT in 78 year-old man and 60 year-old man who received DDD type pacemakers due to sick sinus syndrome, and a case of PMT in 69 year-old man who had suffered complete heart block and received a VDD type pacemaker. In these cases, we investigate symptoms, mechanism of PMT, programed parameters of pacemaker and treatments of PMT.
Aged ; Dichlorodiphenyldichloroethane ; Extremities ; Heart ; Heart Block ; Humans ; Middle Aged ; Sick Sinus Syndrome ; Tachycardia* ; Ventricular Premature Complexes

BACKGROUND: It is very important to evalute the function of the atrioventricular conduction system in selecting appropriate pacemaker, pacing and sensing mode in sick sinus syndrome. It has been reported that atrioventricular conduction abnormalities were commonly accompanied with sinus node dysfunction (SND). However, there were several long term follow-up studies indicating that incidence of AV conduction abnormalities was as low as below 1% a year in patients with SND implanted pacemaker. This study was performed to evaluate the properties of the AV conduction system in patients with SND. SUBJECT AND METHODS: Patients subjected to this study were fifty-eight who underwent electrophysiologic study on suspicion of SND. Sinus node recovery time (SNRT) was defined as the longest time among the times that sinus rhythm reappeared after rapid atrial pacing for 45 seconds with several cycle lengths, and corrected SNRT (cSNRT) was worked out by subtracting sinus cycle length (SCL) from SNRT. Criteria for sinus node dysfunction were 1550 msec or more on SNRT, 550 msec or more on cSNRT and group A (23 cases, 58+/-13 yrs) was defined as SND not retrieved to normal after intravenous administration of atropine 1-2 mg, group B (21 cases, 52+/-14 yrs) was retrieved to normal and group C (14 cases, 54+/-13 yrs) was normal control group. Abnormalities of the AV conduction system were defined as 150 msec or more on AH interval, 500 msec or more on AVblock cycle length (AV-BCL), 450 msec or more on AV nodeeffective refractory period (AVN-ERP). RESULTS: SCL in group A, B, C was 1197+/-340 msec, 1215+/-273 msec, and 898+/-129 msec, respectively at baseline and 886+/-218 msec, 798+/-106 msec, and 722+/-110 msec respectively after atropine administration, showing a significant prolongation of SCL in group A and B at baseline (p<0.001) and group A after atropine administration (p<0.05). SNRT in group A, B, C was 3520+/-1817 msec, 3180+/-2390 msec, and 1282+/-116, respectively at baseline and 4155+/-4281 msec, 1237+/-210 msec, 1020+/-245 msec, respectively after atropine administration, showing a significant prolongation of SNRT in group A and B at baseline (p<0.001) and group A after atropine administration (p<0.05). AH intervals at baseline and after atropine administration were 107+/-27 msec and 100+/-20 msec in group A, 101+/-21 and 91+/-14 in group B, and 118+/-32 and 83+/-23 in group C, showing no significant difference between 3 groups. AV-BCLs at baseline and after atropine administration were 428+/-151 msec and 453+/-301 msec in group A, 525+/-140 and 370+/-53 in group B, and 461+/-120 361+/-94 in group C, showing no significant difference between 3 groups. AVN-ERP was 315+/-57 msec in group A, 343+/-132 msec in group B, 347+/-132 in group C, showing no significant difference between 3 groups. There was no significant difference in the incidences of cases with abnormal AH interval, AV-BCL, AVN-ERP, HV interval between 3 groups. AV block greater than second degree was observed in one patient of group A but none of group B and C. CONCLUSIONS: Atrioventricular conduction abnormalities in patients with sinus node dysfunction were not more common than control subjects. Therefore, atrial pacing rather than ventricular or dual chamber pacing may be safely selected as a permanent pacing mode for sick sinus syndrome with no combined significant AV block.
Administration, Intravenous ; Atrioventricular Block ; Atropine ; Humans ; Incidence ; Sick Sinus Syndrome* ; Sinoatrial Node*

Inappropriate sinus bradycardia associated with degenerative changes in the sinoatrial node has been designated as the sick sinus syndrome. Patients can be asymptomatic but often complain of palpitations and syncopal episodes. A 30 year old parturient, whose pulse rate was about 45-55 beats/min, underwent cesarean section under neuroleptanesthesia. Authors report this case with the review of the relevant literatures.
Adult ; Bradycardia ; Cesarean Section ; Female ; Heart Rate ; Humans ; Pregnancy ; Sick Sinus Syndrome* ; Sinoatrial Node ; Syncope

BACKGROUND: The most widely utilized indexes of sinus node dysfunction are the sinus node recovery time (SNRT) and the corrected sinus node recovery time (CSNRT), which generally require catheterization. Adenosine has negative chronotropic effect on the sinoatrial node. Non-invasive and reliable sinus node function test with intravenous adenosine was investigated. METHODS AND RESULT: The clinical value of rapid intravenous injection of adenosine for assessing sinus node dysfunction was examined in 14 patients with sick sinus syndrome (SSS) and 31 controls. After prophylactic insertion of a temporary pacemaker in the right ventricle, overdrive suppression test was conducted using the standard technique and CSNRT was measured to evaluate the sinus node function. Then, the CSNRT after administration of an intravenous bolus of adenosine (6 mg and 12 mg) was measured. Post-adenosine corrected sinus node recovery time (ADO: SNRT) was calculated by subtracting the basal sinus cycle length from the longest sinus cycle length. When ADO: SNRT over 550 msec was assumed as an indicator of sinus node dysfunction, intravenous injection of 6 mg of adenosine had a sensitivity of 85% and specificity of 100%, and 12 mg of adenosine had a sensitivity of 100% and specificity of 90% for detection of sick sinus syndrome. There were significant differences in ADO: SNRT between patient and control group (6 mg 1501+/-1081 msec vs 64+/-109 msec; 12 mg 4005+/-2055 msec vs 216+/-315 msec, respectively). CONCLUSION: he ADO: SNRT was a highly sensitive and specific index for diagnosing sick sinus syndrome, and should be considered as an alternative to invasive testing in patients with suspected sick sinus syndrome.
Adenosine* ; Catheterization ; Catheters ; Diagnosis* ; Heart Ventricles ; Humans ; Injections, Intravenous ; Sensitivity and Specificity ; Sick Sinus Syndrome* ; Sinoatrial Node