Effect of chronic toluene exposure on heart rhythm parameters.

BACKGROUND: Toluene is used extensively in various industrial processes, and an increasing number of workers are getting exposed to its vapor. Cardiac abnormalities that have been reported in association with toluene exposure (in toxic doses) are atrioventricular conduction abnormalities, sinus bradycardia, ventricular tachycardia, recurrent myocardial infarction, dilated cardiomyopathy, and coronary vasospasm. HYPOTHESIS: We aimed to investigate the effects of chronic toluene exposure on cardiac rhythm. METHODS: In this study, 40 workers in the polishing industry with more than 3 months of exposure to a mixture of organic solvents including toluene and 38 control subjects working in other fields who were matched by age, sex, smoking, habits, and living accommodation were investigated. Twelve-lead surface electrocardiogram and 24-hour Holter recordings were performed to determine QRS duration, PR duration (P and R wave interval on electrocardiograms), P wave dispersion, corrected QT dispersion, and heart rate variability parameters. RESULTS: The maximum heart rate was significantly lower in the toluene-exposed group compared to the control group (130.5 ± 15.1 vs 138.6 ± 16.0, P = 0.02). Corrected low frequency (cLF) and cLF/corrected high frequency (cHF) were also significantly lower in toluene-exposed group (43.6 ± 7.2 vs 50.7 ± 10.5, P = 0.01 and 1.4 ± 0.4 vs 2.2 ± 1.0, P < 0.01, respectively). Mean cHF, root-mean-square successive difference, and standard deviation of all five-minute NN interval means values were significantly higher in the toluene-exposed group (32.8 ± 8.1 vs 25.4 ± 8.2, P ≤ 0.01; 74.0 ± 46.1 vs 60.3 ± 59.4, P = 0.02; and 149.5 ± 77.0 vs 108.9 ± 43.2, P = 0.01, respectively). CONCLUSIONS: This study implies that chronic toluene exposure disturbs cardiac autonomy, particularly by suppressing sympathetic activity, and parasympathetic suppression also occurs with increased exposure duration. We also demonstrated that chronic toluene exposure was not associated with major cardiac arrhythmias and rhythm conduction system disorders.

Permanent atrial standstill with irregular junctional ectopic rhythm mimicking atrial fibrillation.

We present an interesting case of 'pseudo' atrial fibrillation which was further diagnosed as atrial standstill with irregular junctional ectopic rhythm during electrophysiologic study. A 56-year-old woman presented to a health facility with symptoms of palpitation, lightheadedness, and shortness of breath. Upon detection of irregular rhythm with narrow QRS complexes and no visible P waves on the electrocardiogram, newly developed atrial fibrillation was considered and a direct current cardioversion was performed, during which cardiac asystole developed necessitating cardiopulmonary resuscitation. The patient was then transferred to our institution. Echocardiographic examination showed biatrial dilatation, normal left ventricular systolic function, marked left ventricular hypertrophy, severe aortic stenosis, moderate mitral regurgitation, and severe tricuspid regurgitation. The electrocardiogram showed an irregular rhythm with narrow QRS complexes without any fibrillatory f waves and 24-hour Holter monitoring revealed three episodes of ventricular asystole lasting for more than 3.5 seconds. During the electrophysiologic study, no electrical activity was observed at the high and low levels of the right atrial lateral free wall and septal wall. The final diagnosis was established as atrial standstill and irregular junctional ectopic rhythm. The patient refused aortic valve replacement and died due to progression of the underlying disease one year following permanent pacemaker implantation..

Perforations of right heart chambers associated with electrophysiology catheters and temporary transvenous pacing leads.

OBJECTIVES: Perforation of heart chambers is one of the rare complications observed during electrophysiological studies and placement of pacemaker leads. In this study, we performed a retrospective evaluation of patients with catheter-related right heart perforation, aiming to determine its incidence and clinical course. STUDY DESIGN: We reviewed cases with catheter-related cardiac perforations observed at our institution from June 2002 to November 2007. RESULTS: During the study period, a total of 2,385 procedures were performed (1,287 electrophysiologic studies, 1,098 temporary nonballoon-floating pacing lead placements). Eight cardiac perforations were diagnosed, with the overall procedure-based and catheter-based incidences of 0.34% (8/2,385) and 0.14% (8/5,603), respectively. Three of these perforations were related to diagnostic electrophysiology catheters, and five were related to temporary (1 permanent) transvenous pacemaker leads. Seven perforations involved the right ventricle and one involved the right atrium. Three patients in whom right ventricular perforation was detected at a late stage died suddenly after pacemaker lead implantation. One patient underwent surgical exploration because of right atrial perforation. Two patients underwent coronary bypass operation and, in one of these patients, perforation was detected during surgery. Two patients were managed conservatively. CONCLUSION: Although right ventricular perforations detected early have a relatively benign course, those detected late and right atrial perforations require emergent surgical exploration and may have catastrophic consequences.

Isorhythmic dissociation or "pseudo-bygeminy" of depleted pacemaker.

We present an unusual electrocardiogram obtained from a patient with critically depleted pacemaker.

Optimization of repolarization during biventricular pacing: a new target in patients with biventricular devices?

BACKGROUND: Evaluation of repolarization during sequentional biventricular pacing. METHODS: Patients with biventricular devices, and left ventricular leads placed to the basal part of lateral left ventricular wall were enrolled. QRS, QTc, JTc, and corrected Tpeak-Tend intervals were compared during sequentional biventricular, left ventricular, and right ventricular pacing. RESULTS: Five patients with nonischemic and five with ischemic cardiomyopathy due to anterior myocardial infarction were enrolled. No correlation was observed between values of repolarization among patients. The optimal values of repolarization were significantly different from values of echocardiographically guided hemodynamic optimization. Two patients with biventricular pacing-induced ventricular fibrillation were successfully treated by reprogramming of V-V delay according to interventricular delay resulting in shorter Tpeak-Tend interval, although delayed effect of amiodarone in one of these patients cannot be ruled out. CONCLUSIONS: Patients with biventricular devices may be prone to development of ventricular arrhythmias depending on programmed V-V interval. We suggest that optimization of repolarization may be performed in patients with biventricular pacemakers in the absence of backup ICD and those with frequent episodes of ventricular tachyarrhythmias, although this finding deserves further study.

Immediate and follow-up results of repeat percutaneous mitral balloon commissurotomy for restenosis after a succesful first procedure.

BACKGROUND: The widespread use of percutaneous mitral commissurotomy (PMC) has led to an increase in restenosis cases. The data regarding follow-up results of repeat PMC are quite limited. The aim of this retrospective analysis is to evaluate the immediate and midterm results of the second PMC, in patients with symptomatic mitral restenosis after a succesful first procedure. METHODS: Twenty patients (95% female, mean age 37 ± 4 years) who have undergone a second PMC, 6.3 ± 2.5 years after a first successful intervention built the study group. All were in sinus rhythm, with a mean Wilkins score of 8.5 ± 1.2. RESULTS: The valve area increased from 1.2 ± 0.2 to 1.9 ± 0.2 cm(2) and mean gradient decreased from 10.5 ± 3.4 to 6.1 ± 1.1 mmHg. There were no complications except for a transient embolic event without sequela (5%) and two cases (10%) of severe mitral regurgitation. The immediate success rate was 90%. The mean follow-up was 70 ± 29 months (36-156 months). The 5-year restenosis and intervention (repeat PMC or valve replacement) rates were 9.1 ± 5.2% and 3.6 ± 3.3%, respectively. The intervention free 5-year survival in good functional capacity (New York Heart Association [NYHA] I-II) was 95.1 ± 5.5% and restenosis and intervention free 5-year survival with good functional capacity was 89.7 ± 6.8%. CONCLUSIONS: Although from a limited number of selected patients, these findings indicate that repeat PMC is a safe and effective method, with follow-up results similar to a first intervention and should be considered as the first therapeutic option in suitable patients.

Periprocedural considerations during implantation of ICD in a patient with Dextrocardia.

In this case report we present a patient with dextrocardia, who undergone implantation of dual chamber implantable cardioverter-defibrillator (ICD). Here we aimed to underline several specific considerations which must be noted when one considers to implant an ICD in a patient with dextrocardia.

Electromagnetic interference with electrocardiogram recording of exercise test equipment.

Herein, we report a case of pseudosinus tachycardia resulting from an electromagnetic interference between a mobile phone and treadmill device. Electromagnetic interference from a charging mobile phone connected to the same socket with the exercise device turned the recording of a patient to that of pseudosinus tachycardia at approximately twice the rate of actual basal heart rate. Removal of the mobile phone from the socket resulted in normalization of the electrocardiogram.

Successful use of ivabradine in a case of exaggerated autonomic dysfunction.

We present a 30-year-old male with complex and predominantly cardiovascular autonomic dysfunction. He had frequent syncopal attacks and paroxysmal atrial fibrillation (PAF). Physical, electrocardiographic, and echocardiographic findings were unremarkable. Syncopal attacks were precipitated by emotional stress, upright position, and micturition. Electrocardiograms obtained immediately after syncopal events revealed PAF with a low ventricular rate, which spontaneously returned to sinus rhythm without any medication. Syncopal events were suggestive of postural orthostatic tachycardia syndrome (POTS), were induced during upright position, and were associated with a sudden increase in heart rate to approximately 140 beats per minute and a sudden drop in blood pressure. Syncope was also induced during carotid sinus massage (CSM) in the upright position. It was thought that cardiac autonomic dysfunction, with POTS as the main component, was responsible for this clinical condition. Syncopal episodes increased in frequency during treatment with metoprolol. Treatment with ivabradine (5 mg twice a day) resulted in disappearance of syncopal episodes both during upright position and CSM. During six months of follow-up, the patient remained asymptomatic without syncope or atrial fibrillation.

[Arrhythmogenic cardiomyopathy with predominant left ventricular involvement]. / Sol ventrikül tutulumunun ön planda oldugu aritmojenik kardiyomiyopati.

Arrhythmogenic right ventricular cardiomyopathy is a relatively well-defined clinical entity. This disease is characterized with right ventricular involvement and is an important cause of sudden cardiac death in young patients. However, arrhythmogenic cardiomyopathy with left-dominant involvement has recently been better described in the literature. This new presentation may be confused with other diseases such as idiopathic dilated cardiomyopathy. This review outlines left-dominant arrhythmogenic cardiomyopathy in the light of the most recent information.

Chronic mad honey intoxication syndrome: a new form of an old disease?

AIMS: Although cases of acute mad honey intoxication have been reported earlier, chronic mad honey intoxication (CMHI) syndrome has not been described and we address this issue only in this study. METHODS AND RESULTS: We prospectively evaluated the history of non-commercial honey intake in all patients referred to our institution for investigation of slow heart rate or atrioventricular (AV) conduction abnormalities. Between April 2008 and December 2008, 173 patients were referred to our institution for assessment of sinus bradycardia and various degrees of AV block and/or permanent pacemaker implantation. All patients were questioned about history of honey intake. Detailed evaluation revealed a history of daily honey intake for a long period of time in five of the patients (2.8%). This non-commercial honey was made by different amateur beekeepers in eastern Back Sea region of Turkey. Discontinuation of honey intake resulted in prompt normalization of conduction and significant symptomatic improvement. None of the patients were admitted to hospital and all were asymptomatic during 3 months follow-up. Holter monitoring for 24-h revealed no abnormality at first and third month. CONCLUSIONS: This is the first report of CMHI. This issue should be suggested during assessment of patients with unexpected conduction abnormalities, because abandonment of honey intake results in prompt symptomatic and electrocardiographic improvement.

Early development of pacemaker Reel syndrome in an elderly patient with cognitive impairment.

Reel syndrome is a rare form of Twiddler's syndrome and is characterized by rotation of permanent pacemaker on its transverse axis and rolling of the electrode around the generator. An 83-year-old man with severely impaired mental status, agitation, and uncontrolled movement of extremities underwent pacemaker implantation for symptomatic atrial fibrillation. The pacemaker generator was fixed to the pectoral fascia with nonabsorbable ligatures. On the next day, failure to capture the ventricle was noted. Fluoroscopic examination showed coiling of the electrode around the generator. During urgent intervention, the ligature of the generator was observed to be released from the pectoral fascia. The pacemaker lead was not damaged; therefore, the same lead was re-implanted, connected to the generator, and carefully fixed to the pectoral fascia. The patient showed rapid clinical improvement together with his mental status. No abnormality was detected during three months of follow-up. Patients with impaired consciousness, children, and older persons require a close follow-up because of their propensity to this serious and life-threatening complication.

An unusual cause of OptiVol alarm: increased intra-abdominal pressure associated with irritable bowel syndrome.

Monitoring intrathoracic impedance has become an integral part of follow-up of patients with implantable cardioverter defibrillator (ICD) or cardiac resynchronization therapy/defibrillator due to heart failure. However, several noncardiac factors may influence intrathoracic impedance. We report on an unusual cause of decrease in intrathoracic impedance in a 54-year-old male patient following successful implantation of biventricular ICD for heart failure symptoms due to nonischemic dilated cardiomyopathy and severely impaired left ventricular systolic function. During the follow-up period, the patient presented several times with the OptiVol alarm due to an increase in the OptiVol fluid index, in the absence of symptoms or signs of heart failure. Further inquiry into the possible causes of decreased intrathoracic impedance revealed that the patient had frequent episodes of irritable bowel syndrome, which increased intra-abdominal pressure, leading to elevation of diaphragm and subsequent compression of intrathoracic organs, and thus to a decrease in intrathoracic impedance.

Complete transection of epicardial pacing lead during pregnancy.

Herein, we presented a case of pregnancy associated complete transection of epicardial pacing lead.

Unusual electrocardiographic presentation of pacemaker battery depletion with lead failure: pacing spike, artefact or native QRS? A short communication.

Herein we report an unusual electrocardiographic presentation of a patient with pacemaker battery depletion and lead insulation failure.

Diagnostic trilemma: isorhythmic AV dissociation mimicking intermittent preexcitation and acute inferior myocardial infarction.

In this case report, we present a patient with intermittent isorhythmic atrioventricular dissociation mimicking two different electrocardiographic entities: ventricular preexcitation pattern and recurrent acute inferior myocardial infarction.

Heparin-induced thrombocytopenia after MitraClip: A case report.

Heparin-induced thrombocytopenia (HIT) and heparin-induced thrombocytopenia and thrombosis are potentially fatal adverse reactions to heparin therapy caused by the formation of polyclonal antibodies against the platelet factor 4-heparin complex. Fatal limb and organ damage or death may occur as a result of this immunological drug reaction. Described in this case report is the management of a patient who developed HIT after undergoing a MitraClip transcatheter mitral valve repair. The aim was to encourage clinicians to pay special attention to a frail patient who receives heparin therapy and to advise clinicians that clinical scores and laboratory tests should be used as a complement for certain diagnosis. The decision about continuation or cessation of heparin therapy is an important cornerstone for hospitalized patients with HIT.