Cardiac arrhythmias are a common problem in the neurological intensive care unit and represent a major cause of ischemic stroke. Significant arrhythmias are most likely to occur in elderly patients. In this review, we focus on three arrhythmias: premature beats, atrial fibrillation, and QT prolongation. The goal of this review is to provide a current concept of diagnosis and acute management of arrhythmias in the neurological intensive care unit.
Aged ; Arrhythmias, Cardiac ; Atrial Fibrillation ; Atrial Premature Complexes ; Cardiac Complexes, Premature ; Critical Care ; Diagnosis ; Humans ; Intensive Care Units ; Stroke ; Ventricular Premature Complexes

Arrhythmias in the neonatal period are not uncommon, and may occur in neonates with a normal heart or in those with structural heart disease. Neonatal arrhythmias are classified as either benign or nonbenign. Benign arrhythmias include sinus arrhythmia, premature atrial contraction, premature ventricular contraction, and junctional rhythm; these arrhythmias have no clinical significance and do not need therapy. Supraventricular tachycardia, ventricular tachycardia, atrioventricular conduction abnormalities, and genetic arrhythmia such as congenital long-QT syndrome are classified as nonbenign arrhythmias. Although most neonatal arrhythmias are asymptomatic and rarely life-threatening, the prognosis depends on the early recognition and proper management of the condition in some serious cases. Precise diagnosis with risk stratification of patients with nonbenign neonatal arrhythmia is needed to reduce morbidity and mortality. In this article, I review the current understanding of the common clinical presentation, etiology, natural history, and management of neonatal arrhythmias in the absence of an underlying congenital heart disease.
Arrhythmia, Sinus ; Arrhythmias, Cardiac* ; Atrial Premature Complexes ; Diagnosis* ; Heart ; Heart Defects, Congenital ; Heart Diseases ; Humans ; Infant, Newborn ; Mortality ; Natural History ; Prognosis ; Tachycardia, Supraventricular ; Tachycardia, Ventricular ; Ventricular Premature Complexes

PURPOSE: This study aimed to analyze changes in QRS duration and cardiothoracic ratio (CTR) following pulmonary valve replacement (PVR) in patients with tetralogy of Fallot (TOF). METHODS: Children and adolescents who had previously undergone total repair for TOF (n=67; median age, 16 years) who required elective PVR for pulmonary regurgitation and/or right ventricular out tract obstruction were included in this study. The QRS duration and CTR were measured pre- and postoperatively and postoperative changes were evaluated. RESULTS: Following PVR, the CTR significantly decreased (pre-PVR 57.2%±6.2%, post-PVR 53.8%±5.5%, P=0.002). The postoperative QRS duration showed a tendency to decrease (pre-PVR 162.7±26.4 msec, post-PVR 156.4±24.4 msec, P=0.124). QRS duration was greater than 180 msec in 6 patients prior to PVR. Of these, 5 patients showed a decrease in QRS duration following PVR; QRS duration was less than 180 msec in 2 patients, and QRS duration remained greater than 180 msec in 3 patients, including 2 patients with diffuse postoperative right ventricular outflow tract hypokinesis. Six patients had coexisting arrhythmias before PVR; 2 patients, atrial tachycardia; 3 patients, premature ventricular contraction; and 1 patient, premature atrial contraction. None of the patients presented with arrhythmia following PVR. CONCLUSION: The CTR and QRS duration reduced following PVR. However, QRS duration may not decrease below 180 msec after PVR, particularly in patients with right ventricular outflow tract hypokinesis. The CTR and ECG may provide additional clinical information on changes in right ventricular volume and/or pressure in these patients.
Adolescent ; Arrhythmias, Cardiac ; Atrial Premature Complexes ; Child ; Electrocardiography ; Heart Valve Prosthesis Implantation ; Humans ; Pulmonary Valve Insufficiency* ; Pulmonary Valve* ; Tachycardia ; Tetralogy of Fallot* ; Ventricular Premature Complexes

The excitatory influence on heart rate is generally considered by beta-adrenergic neuroreceptors of Ahlquist's classificantion. Blockade of the beta adrenergic system would therefore be expected to alter heart rate and consequently to have an effect of patients with a variety of cardiac arrhythmias. In 1964 a clinically useable agent was produced by the name of propranolol which would effectively block beta action of adrenergic system and safe from side effects. The purpose of this study is to determine and estimate the immediate therapeutic effects of propranolol on 29 cases with various cardiac arrhythmias, administered intravenously. The following results were obtained: 1. It is apparent that propranolol by the intravenous route offers a rapid means of inducing A-V block and hence a reduction of the ventricular response in atrial fibrillation and atrial flutter. 2. Propranolol may be of value in improving digitalis-resistant atrial tachyarrhythmias with the therapeutic supplement. 3. Propranolol diminishes the automaticity of ectopic pacemakers because this is evident in the slowing of atrial rate or conversion of paroxysmal atrial tachycardia to sinus rhythm and the abolition or diminution of ventricular extrasystoles. 4. Digitalis-induced ventricular arrhythmias respond to propranolol well, and propranolol may well be the drug of choice in treating digitalis-induced ventricular arrhythmias. 5. Ventricular arrhythmias not related to digitalis were not satisfactorily treated with propranolol in our series. 6. Side effects associated with propranolol treatment were not remarkable except for development of transient hypertension in 2 cases.
Arrhythmias, Cardiac ; Atrial Fibrillation ; Atrial Flutter ; Digitalis ; Heart Rate ; Humans ; Hypertension ; Propranolol* ; Sensory Receptor Cells ; Tachycardia ; Ventricular Premature Complexes

BACKGROUND AND OBJECTIVES: Prolonging of the corrected QT interval (QTc) has been reported after cardiac surgery in some studies. However, there have not been many studies on infant open cardiac surgery for ventricular septal defect (VSD) repair. This study was performed to define the changes in QTc and to find related post-surgery factors in this patient group. SUBJECTS AND METHODS: From 2008 to 2012, 154 infants underwent VSD repair at the Severance Cardiovascular Hospital. This study includes 105 of these cases. QTc was measured in these patients retrospectively. Demographic data and peri-procedural data, such as Aristotle score, cross-clamp time and bypass time, were analyzed. The exclusion criteria included multiple and small VSDs that underwent direct closure. RESULTS: Mean post-operative QTc was increased compared to the pre-operative measurements (from 413.6+/-2.3 to 444.9+/-2.5, p<0.001). In multiple linear regression, the comprehensive Aristotle score was associated with increasing QTc (p=0.047). The incidence of transient arrhythmia, such as atrial tachycardia, junctional ectopic tachycardia, premature atrial contraction, or premature ventricular contraction, was associated with QTc prolongation (p=0.005). Prolonged QTc was also associated with cross-clamp time (p=0.008) and low weight (p=0.042). Total length of stay at the intensive care unit and intubation time after surgery were not associated with QTc prolongation. CONCLUSION: Prolonged QTc could be seen after VSD repair in infants. This phenomenon was associated with peri-procedural factors such as the Aristotle score and cross-clamp time. Patients with QTc prolongation after cardiac surgery had an increased tendency towards arrhythmogenicity in the post-operative period.
Arrhythmias, Cardiac ; Atrial Premature Complexes ; Electrocardiography ; Heart Septal Defects, Ventricular* ; Humans ; Incidence ; Infant* ; Intensive Care Units ; Intubation ; Length of Stay ; Linear Models ; Retrospective Studies ; Tachycardia ; Tachycardia, Ectopic Junctional ; Thoracic Surgery ; Ventricular Premature Complexes

We reviewed 26 cases of cardiac rhabdomyoma in children which were diagnosed between 1986 and 1991 in Seoul National University Children's Hospital. Twenty-two cases were associated with tuberous sclerosis. Total tumor count was 58 and mean tumor count per patient was "daehakgyo".23. Their cardiac rhabdomyomas were diagnosed from fetal period through 12 years after birth. Median age was 9."uiwon" months. Fifteen patients were males and rest 11 patients were females. Cardiac symtoms and signs at initial diagnosis were present in 12 cases. They consisted of cardiac murmur in "hakgyo", arrhythmia in 8 and congestive heart failure in "daehakgyo" cases (one with murmur and the other with arrhythmia). Cardiomegaly was seen in 9 cases on chest X-ray and other "byeongwon" case showed abnormal left cardiac border. Electrocardiography and 24 hour Holter monitorings showed arrhythmia in 15 cases. Clinically significant arrhythmias were found in 7 cases on 24 hour Holter monitorings. They consisted of 1with frequent premature ventricular contractions, "daehakgyo uigwadaehak" with frequent premature atrial contractions, "daehakgyo" with atrial tachycardia and "daehakgyo uigwadaehak" with atrio-ventricular block ("daehakgyo" cases of atrio-ventricular block had other arrhythmias also). The locations of tumors were left ventricle in 21, interventricular septum in 21, right ventricle in 13 and atrium in "daehakgyo uigwadaehak" tumors. Mean tumor count per patient in fetal period and infancy was "daehakgyo".86 and it was statistically much more than that after infancy which was "byeongwon".5. Mean tumor area which was calculated on two dimensional echocardiography was larger in fetal period and infancy(128.9 +/- 38.2mm2)than that after infancy(47.8 +/- 11.2mm2). Mean relative tumor area to aortic root dimension was also significantly larger in fetal period and infancy than that after infancy ("daehakgyo".07vs 0.30). In tuberous sclerosis, mean mass area and mean relartive tumor area to aortic root dimension in fetal period and infancy was significantly larger than those in patients after infancy. Of 26 cases, tumorectomy was done in "daehakgyo uigwadaehak" cases due to hemodynamic obstruction and arrhythmia. One case died immediately after operation and the other "daehakgyo" cases are still alive with the follow up period of 30 and 44 months each. Of the 7 patients with significant arrhythmia on 24 hour Holter monitorings, pacemaker insertion was done in "byeongwon" case who received tumorectomy and other 1 case was treated with anti-arrhythmic drugs. All the other patients did not need anti-arrhythmic drugs or other management.
Arrhythmias, Cardiac ; Atrial Premature Complexes ; Cardiomegaly ; Child* ; Diagnosis ; Echocardiography ; Electrocardiography ; Female ; Follow-Up Studies ; Heart Failure ; Heart Murmurs ; Heart Ventricles ; Hemodynamics ; Humans ; Male ; Parturition ; Rhabdomyoma* ; Seoul ; Tachycardia ; Thorax ; Tuberous Sclerosis ; Ventricular Premature Complexes

PURPOSE: Bone Marrow Transplantation (BMT) is very stressful treatment to the patients' hearts. The aim of this study was to evaluate the serial change of cardiac function and morphology on echocardiography and to propose the guidelines of echocardiographic monitoring in BMT patients. METHOD: We divided the 64 patients (M:F=42:22, mean age 33+/-9, 25 AML, 8 ALL, 19 CML, 12 others) with hematologic diseases into early group (M:F=22:7, mean age=33+/-9) whose follow up echocardiograms were taken within 90 days, and late group (M:F=20:15, mean age=33+/-8) whose follow up echocardiograms were taken beyond 90 days after BMT. In both groups, changes of left ventricular dimensions, ejection fraction, wall thickness, E/A ratio and deceleration time (DT) were measured before and after BMT. RESULTS: Cardiac complications were observed in 18 pateints after BMT. The pericardial effusion in 6, benign arrhythmias in 6, including sinus arrhythmia, premature ventricular contraction, premature atrial contraction developed in the early group, but 5 of 6 patients who had ejection fraction less than 40% were in the late group. After BMT, the thickness of interventricular septum and left ventricular posterior wall was significantly increased (p<0.05) and ejection fraction and E/A ratio was significantly decreased (p<0.05, respectively) in the early group. In the late group the thickness of interventricular septum returned to normal range, but ejection fraction was significantly decreased (p<0.05) and deceleration time significantly (p<0.05) shortened. CONCLUSION: This study shows that the early cardiac change after BMT is mainly decrease of LV systolic function with hypertrophy and the late change is not only decrease of systolic function but also change of diastolic parameters. Therefore the serial assessment of cardiac function and morphology using transthoracic echocardiography is essential for the early diagnosis of cardiac toxicity, especially early after BMT.
Arrhythmia, Sinus ; Arrhythmias, Cardiac ; Atrial Premature Complexes ; Bone Marrow Transplantation ; Bone Marrow* ; Deceleration ; Early Diagnosis ; Echocardiography* ; Follow-Up Studies ; Heart ; Hematologic Diseases ; Humans ; Hypertrophy ; Pericardial Effusion ; Reference Values ; Ventricular Premature Complexes

The effect of oral mexiletin was evaluated by a 10-day double-blind cross-over protocol on 10 subjects with chronic stable high-frequency ventricular premature beats referred to our cardiology clinic from February through July, 1982. Total daily doses were either 450mg or 600mg in three divided portions depending on body weight. The frequency of the premature ventricular beats was measured by 3 separate 24-hour ambulatory EKG recordings by dual-channel Holter monitor on each patient. Mexiletine was judged to be effective in suppressing the ventricular arrhythmias when the 24-hour PVC-counts during the study-drug period showed a decrease by 80% and the hourly average PVC-counts by 70% compared with those of the equivalent intervals of both the baseline and the placebo periods. Mexiletine was effective in 5 of the 10 subjects. Mild tremor and anorexia were noted in 2 patients, but they were able to comply with the study protocol in spite of these minor side effects. Blood level measurements were not done in this study for lack of such facility, the utilization of which would undoubtedly enhance the therapeutic effectiveness of the antiarrhythmic agent in the individualization of treatment.
Anorexia ; Arrhythmias, Cardiac ; Body Weight ; Cardiac Complexes, Premature* ; Cardiology ; Electrocardiography ; Humans ; Mexiletine* ; Tremor ; Ventricular Premature Complexes

Ventricular premature beats(VPB) are the most common cardiac arrhythmia and frequently found in apparently normal healthy persons as well as in various heart diseases. Postectopic potentiation of ventricular contraction has widely reported by electrocardiography. In this study, the authors performed comparative assessment of the left ventricular function at the preextrasystolic, extrasystolic and postextrasystolic beats by M-mode echocardiography and electrocardiography. The results obtained were as followings; 1) Among 22 patients of isolated, unifocal ventricular premature beats with fully compensatory pause, male were 6 and female 16, mean age being 47.2 years. 2) Hypertensive heart disease was the most common underlying disease of ventricular premature beats(5 patients) and the others were valvular heart diaeases(3), ischemic heart diseases(3), cardiomyopathy(2), intracerebral hemorrhagy(1), atrial septal defect of secundumtype(1), cor pulmonale(1), pericarditis(1), 1degree A-V block(1) and enteric fever(1). In 3 patients the causes were not clarified. 3) R wave amplitude was higher in the postextrasystolic beat(2.02+/-0.79cm) than preestrasystolic beat(1.86+/-0.66cm) 4) PEP/LVET ratio showed more decrease(18%) in postextrasystolic beat than that of preextrasystole. 5) Diastolic filling time of mitral valve was more reduced in the extrasystole than preextrasystole, but that of postextrasystole exceeded the preextrastystole. 6) Aortic cusps separation was more decreased in the extrasystole than preextrasystole and slightly more increased in the postextrasystole than preextrasystole. 7) LVID, LSa, ENa, DeltaEN/Deltat, LVEDV, SV and LV mass showed more decrease in extrasystole compared with those in pre-and postextrasystole, which was higher than preextrasystole. But LVESV was slightly lower in extrasystole than preextrasystole. 8) In extrasystolic beat, LVEDV, LVESV, stroke volume, and ejection fraction of ventri cular premature beat were 15.77%, 0.18%, 24.05% and 12.21% lower, respectively, than those of preextrasystole. And in the postextrasystole, LVEDV, LVESV, stroke volume and ejection fraction were 23.35%, 2.42%, 28.51% and 10.4% higher, respectively, than these of preextrasystole.
Arrhythmias, Cardiac ; Cardiac Complexes, Premature* ; Echocardiography* ; Electrocardiography ; Female ; Heart ; Heart Diseases ; Heart Septal Defects, Atrial ; Humans ; Male ; Mitral Valve ; Stroke Volume ; Ventricular Function, Left*

Positive end expiratory pressure (PEEP) has been used to prevent and treat venous air embolism in patients in the sitting position undergoing neurosurgical operations However, the safety of PEEP has recently been questioned, because of concern that PEEP might incresae right atrial pressure more than left atrial pressure, thereby predisposing patients with a probe-patent foramen ovale to paradoxical air embolism. But it is controversial and needs further evaluation. In a prior study in rabbits with various venous air volume, the authors found that suddenly decreased mean arterial pressure and arterial PO2 showed peaked P wave, arrhythmias, ST depression and premature ventricular contraction on the EKG. In the present study, the authors examined the effects of 0, 3 and 5 cmHO PEEP (PEEP0, PEEP3, and PEEP5,) in 30 rabbits positioned supine with intravenous 0.5 mg/kg of air injection. In a prior study, we found that 0.5 mg/kg of air injection has serious change but showed low mortality. The measurements were obtained by the precordial doppler ultrasound, end tidal PCO2, mean arterial pressure, arterial PCO2, arterial PO2, and EKG. The results were as follow; 1) Doppler ultrasound was the most sensitive device even with PEEP and end tidal PCO2 was higher with PEEP5 than with PEEP3 and PEEP0 after suddenly decreased by the air injection. In PEEP statistic singnificance was observed (p<0.05). 2) The mean arterial pressure was significantly decreased by the air injection in PEEP0 PEEP3 and PEEP5 but there were no significant differences in all groups. It seemed likely due to low PEEP. 3) In PaCO2, slightly higher PaCO2 was observed in PEEP5 than in PEEP3 and PEEP. No statistic significance was obaerved. In PaO2, significant decrease was observed in all group but in PEEP3 small decrease was observed. 4) The incidence of bradycardia and ST depression was less in PEEP3 and PEEP5 than in PEEP0. In PEEP5, PVC was appeared relatively short duration than other group due to the air lock phenomenon. It was suspeeted that air was more freely passed according to increased right ventricular pressure after air lock. Authors conclude that PEEP has a benefit effect for the prevention of venous air embolism but after the occurence there is little benefit in the treatment.
Arrhythmias, Cardiac ; Arterial Pressure ; Atrial Pressure ; Bradycardia ; Depression ; Electrocardiography* ; Embolism, Air* ; Foramen Ovale ; Humans ; Incidence ; Mortality ; Positive-Pressure Respiration ; Rabbits* ; Ultrasonography ; Ventricular Premature Complexes ; Ventricular Pressure