Incidence Of Serious Arrhythmias Research Articles

Development and validation of a risk prediction nomogram for serious arrhythmias in acute digoxin toxicity among pediatrics: A multicenter study

Digoxin is a cardiac glycoside obtained from the leaves of the foxglove plant, Digitalis lanata. Several studies have described the safety of digoxin including various life-threatening events, notably cardiac arrhythmias. Early identification of high-risk patients and subsequent initiation of the utmost medical care are associated with a better prognosis. The assessment of serum digoxin levels, which is not always convenient, is the only tool used to evaluate the severity of digoxin exposure. However, the feasibility of this tool, particularly in resource-restricted countries, remains unclear. Therefore, the current study aimed to establish and validate a feasible alternative tool, a bedside nomogram, to identify pediatric patients diagnosed with acute digoxin intoxication who are at risk of developing serious arrhythmias. This was a two-phase, multicenter, retrospective study. The prevalence of serious arrhythmias was approximately 17%. Patients diagnosed with serious arrhythmias showed significantly higher serum digoxin, random blood glucose, and potassium levels but lower sodium, magnesium, and hemoglobin levels. Serious arrhythmias were associated with significantly lower P-R intervals, shorter QTc intervals, and more frequent digoxin effects (p < 0.05). The proposed nomogram showed that combining age and initial random blood glucose, sodium, and potassium levels could predict the future incidence of serious arrhythmia with an accuracy of 96.2% (sensitivity = 94.4%, specificity = 96.5%), an area under the curve (AUC) of 0.977, and p < 0.001. Validation of the proposed nomogram yielded an AUC for the nomogram probability of approximately 81%, and the AUC for the predicted probability using the developed model was 98.3%, indicating that both the validated model and the developed nomogram were significant predictors of serious arrhythmia. The utility of using the four-factor nomogram to determine the risk of serious arrhythmia in children exposed to an overdose of digoxin is comparable, if not superior, to the serum digoxin level.

Weighing the adverse cardiac effects of fluoroquinolones: A risk perspective.

A rare side effect of fluoroquinolone (FQ) antibiotics is QT prolongation, which may result in serious arrhythmias. Most published comparative trials describe the relative risks among the drug class but do not focus on the incidence of serious arrhythmias. It is important for the prescriber to have a sense not only of relative risk but also of incidence to balance the risks against the other attributes of the individual members of the drug class. A review of English-language literature was performed to identify trials that provide data on the relative risk and, when able to be calculated, the incidence of adverse cardiac events among the commonly used FQs. Moxifloxacin had a several-fold higher risk of cardiac arrhythmias than levofloxacin or ciprofloxacin in randomized trials. However, the actual event rate was low in 2 of 3 studies. Given inconsistencies among the studies and the relative rarity of the events, the clinician need not base the choice of drug primarily on concern for a cardiac arrhythmia except in patients at the highest risk of such an event.

O104 Influence of the Long Interdialytic Break on the Incidence of Serious Arrhythmias and Sudden Cardiac Death in Patients with Chronic Kidney Disease (CKD) undergoing Haemodialysis

Introduction: Chronic kidney disease (CKD) patients on haemodialysis (HD) have a high risk of sudden cardiac death (SCD). Traditional SCD risk factors donot adequately explain this but a unique risk factor may be a longer interval between HD sessions (interdialytic period, IDP). Inherent in conventional HD (thrice-weekly) are two 48-hour (short) breaks and one 72-hour (long) break between the start of HD sessions. Changes in electrolyte balance, ventricular repolarization (VR) and autonomic tone (AT) may be more profound after the longer IDP. Objectives:We used an implantable loop recorder (ILR) to define the incidence and timing of significant arrhythmias in a HD population, comparing the impact of the long vs short IDP (event time distribution-ETD). We used Ambulatory 24-hour Holter monitoring to evaluate markers of arrhythmic risk according to ETD. Methods: 50 CKD patients undergoing thrice-weekly conventional HD were recruited & underwent ILR insertion with regular fortnightly device follow-up. Pts with left ventricular ejection fraction 16 beats <30sec) in 7 (14%). The combined primary end point occurred in 14 pts (28%) with 385/615 (63%) events occurring during the long IDP (p<0.001). No episodes of long QT related polymorphic VT were observed.

Incidence of serious arrhythmias after successful revascularization in patients with NSTEMI

Incidence of serious arrhythmias after successful revascularization in patients with NSTEMI

Should All ED Patients Be on a Cardiac Monitor? No.

Most patients who present to emergency departments with chest pain undergo cardiac monitoring during their ED evaluation so that sudden dangerous arrhythmias can be identified and treated rapidly. The incidence of serious arrhythmia in hospitalized patients on telemetry is very low (<1%), but the incidence in ED patients is not known. Researchers sought to develop a decision rule that would identify patients …

Practical Application of Holter Monitoring in Dogs and Cats

Holter monitoring is a valuable noninvasive tool for the monitoring of the cardiac rhythm over a prolonged period during normal daily activities. The advent of this diagnostic test has demonstrated that the incidence of serious arrhythmias is much greater than previously determined using routine electrocardiography. A resting electrocardiogram is typically recorded for several seconds to several minutes and is likely to miss or underestimate the underlying arrhythmia. This article will present the clinical indications, equipment, technical application, and assessment of holter monitoring.

Arrhythmias after surgical correction of complete transposition—follow-up into adolescence

SummaryThe long-term natural progression of cardiac rhythm and the incidence of serious arrhythmias in relation to previous procedures and associated heart defects were studied in a group of 76 patients after an arterial switch operation for complete transposition and compared to a group of 24 patients who had undergone intraatrial corrections (Mustard or Senning operation). Standard and 24-hour ambulatory electrocardiograms were reviewed. Mean follow-up was 7.9 years (range 2-16) after an arterial switch and 15.2 years (range 6-26) following the Mustard or Senning procedures. One patient died after an arterial switch from pulmonary hypertension (age 9.9 years), and three patients died suddenly, presumably from arrhythmias, following atrial redirection procedures (ages 13, 18 and 20 years). Symptomatic arrhythmias were not seen after the arterial switch operation. Three patients required pacemaker implantation after atrial redirection, and a further two required medication to control tachyarrhythmias. Survival analysis of sequential electrocardiograms showed a mean maintenance of sinus rhythm during 12.9 years (95% confidence interval 11.4-14.5) after the arterial switch and 9.0 years (7.3-10.7) after atrial procedures (p=0.003). Development of heart rate was significantly different (p=0.001), with higher rates in adolescents after an arterial switch. Twenty-four-hour recordings were abnormal in five of 72 patients following arterial correction, disclosing excessive ventricular extrasystoles in four (three monomorphic, one polymorphic) and a wandering pacemaker in one. After atrial procedures, 11 of 19 were abnormal (p&lt;0.001), with sinus or atrial bradycardia in eight, atrial flutter in two, and monomorphic ventricular tachycardias in one. Abnormal findings on either 12-lead or 24-hour electrocardiograms were seen in 22% of patients following an arterial switch procedure and 83% of patients undergoing atrial redirection (p&lt;0.001). Sinus rhythm, therefore, is preserved longer and arrhythmias are less frequent and less severe after the arterial switch operation than after the Mustard or Senning operations.

Hypomagnesaemia and fits complicating paediatric cardiac surgery.

Cardiac arrhythmias and neurological irritability frequentlycomplicatethe recoveryof children after cardiac operations. Hypomagnesaemia has been documented in up to 65010 of critically ill hospital inpatients, and has been reported to complicate the administration of loop diuretics and intravenous catecholamtnes.? Hypomagnesaemia has also been shown to be associated with an increased incidence of serious arrhythmias after myocardial infarction in adults and of fits in neonates.t However, the incidence of hypomagnesaemia and its relationship to cardiac arrhythmias and neurological symptoms in children recovering from cardiac operations has not been previously described. We studied prospectively a group of infants recovering on the intensive care unit (ICU) after closed heart operations to answer these questions.

Magnesium substitution in acute ischaemic heart syndromes

It has recently been suggested that intravenous infusion of magnesium may reduce mortality and the incidence of serious arrhythmias in patients with ischaemic heart disease and acute myocardial infarction. In the present double-blind, placebo-controlled study, 298 patients with suspected acute myocardial infarction were randomized to receive either intravenous magnesium chloride (80 mmol.24 h-1) or placebo. Infusions were started immediately after admission to the coronary care unit. One hundred and fifty patients received magnesium and 148 the placebo. Ischaemic heart disease was diagnosed in 244 patients. Acute myocardial infarction was observed among 83 patients in the magnesium group and 79 in the placebo group. Both treatment groups were comparable regarding sex, age, clinical status, previous cardiac disease and medication. Serum magnesium was significantly raised during magnesium infusion compared to placebo (P less than 0.01). Fatal events were only observed among patients with myocardial infarction, but neither the in-hospital mortality (magnesium: 12.1%; placebo 10.1%) nor the mortality after a follow-up period of 245 days (median observation time) was affected by magnesium substitution. Magnesium infusion was accompanied by a significantly increased incidence of atrioventricular conduction disturbances. The results suggest that patients suffering from acute ischaemic heart syndromes do not benefit from intravenous magnesium supplementation.

Myocardial infarction in childhood: clinical analysis of 17 cases and medium term follow up of survivors.

Between 1979 and 1989 17 patients aged two months to 12 years with acute myocardial infarction of any cause (other than after cardiac surgery) were seen at a children's hospital. Eight died from three days to three years after diagnosis (overall mortality 47%). The nine survivors, now aged 2-17 years, have been followed for one to 10 years (mean follow up five years) after infarction. The commonest causes of myocardial infarction in this series were anomalous origin of left coronary artery from the pulmonary artery (six patients (35%] and Kawasaki disease (five patients (27%]. The main symptoms of acute myocardial infarction were dyspnoea, vomiting, and difficulty feeding. Diagnosis was made in all patients by electrocardiography and confirmed by echocardiography, cardiac catheterisation, or at operation. All survivors were symptom free with excellent exercise capacity. The left ventricular ejection fraction in survivors ranged from 21% to 66%, and only one child was on regular cardiac medications. There were no cases of late sudden death. Twenty four hour Holter monitoring performed on survivors was normal (seven) or showed minor abnormalities only (one), suggesting that serious arrhythmia is rare after paediatric myocardial infarction. Myocardial infarction in children had a high early mortality; however, the incidence of serious arrhythmia was low in the survivors, who had a good exercise tolerance even when the left ventricular ejection fraction was low.

Ventricular fibrillation in coronary angiography: what is the role of contrast medium?

A retrospective review of patients with coronary angiography was undertaken to establish the incidence of ventricular fibrillation and other serious arrhythmias and to identify possible causative factors, in particular whether the use of non-ionic contrast medium increased the risk of a serious arrhythmia. Out of 3660 patients reviewed there were 10 cases of ventricular fibrillation. In all cases, there were identifiable technical factors thought to have accounted for the arrhythmia. There were no cases of ventricular fibrillation complicating a technically satisfactory injection of ionic or non-ionic contrast medium. There was no significant difference in the incidence of serious arrhythmias between patients given ionic and those given non-ionic contrast medium.

Magnesium in the Prevention of Lethal Arrhythmias in Acute Myocardial Infarction

Seven of 48 patients (14.6%) with acute myocardial infarction who were given 2.4 g of magnesium sulfate as a single intravenous dose had potentially lethal arrhythmias during the first 24 hours after admission, whereas 16 (34.8%) of 46 patients receiving placebo had similar arrhythmias. In addition, 14 of these 16 patients in the placebo group had their first arrhythmia (in the intensive coronary-care unit) within two hours after the start of the study, whereas in the magnesium-treated group, there were no such arrhythmias until some four hours later. The higher the lymphocyte potassium concentration, the greater the reduction in the incidence of arrhythmias. Serum magnesium levels increased by 16.5% and lymphocyte magnesium concentrations by 72% in the magnesium treated group. Intravenous magnesium reduces the incidence of serious arrhythmias after acute myocardial infarction.

Twenty-four hour ambulatory ECG monitoring of junior high school students in Miki City.

To evaluate incidence of serious arrhythmias among school age youths, 24-hour ambulatory ECG monitoring was performed in 100 junior high school students, including 60 subjects with some ECG abnormalities and 40 without. With this monitoring 2 cases with multifocal VPCs and 2 cases with paired VPCs or nonsustained ventricular tachycardia were found; the case with VT died suddenly after having been lost during careful follow up. It is emphasized from these results that ambulatory ECG monitoring is quite useful in selected cases in this age group and careful follow up of students with advanced grade VPCs is very important.

Clinical superiority of a new nonionic contrast agent (iopamidol) for cardiac angiography

The hemodynamic and electrophysiologic alterations induced by ionic contrast agents during cardiac angiography are well described. Recently nonionic contrast agents have become available for cardiac angiography. To evaluate the safety of these new agents, a double-blind randomized study was performed comparing a new nonionic agent (iopamidol) with a commonly used ionic contrast agent (Renografin-76). Eighty-one patients undergoing left ventriculography and coronary angiography were included; 41 received iopamidol and 40 received sodium meglumine diatrizoate (Renografin-76). After left ventriculography, there was a decrease in the arterial pressure with both contrast agents. However, the severity and the duration of hypotension were both significantly greater with Renografin-76 compared with the new nonionic agent (p less than 0.001). After selective injections of the coronary arteries, electrocardiographic analysis demonstrated that the increase in the QT interval (p less than 0.0002) and the changes in both the ST segment and T wave amplitude (p less than 0.001) were significantly greater in the Renografin-76 group compared with the iopamidol group. During coronary angiography, 8 of the 40 patients receiving Renografin-76 required temporary pacing for sinus pauses of 2.5 seconds or more, and 2 of the 40 also developed ventricular fibrillation. None of the 41 patients receiving iopamidol had these complications. This report demonstrates that the electrocardiographic changes, the severity and duration of hypotension and the incidence of serious arrhythmias are significantly greater with Renografin-76 than with iopamidol. Thus, this new nonionic agent appears to enhance the safety of cardiac angiography.

Prinzmetal's variant angina.

A series of 12 consecutive patients with Prinzmetal's variant angina is presented. There was a preponderance of males (eight/12) and individuals less than 60 years of age (nine/12). Delay in diagnosis was frequent, primarily due to difficulty in achieving a proper 12 lead ECG recording of the attack which often occurred late at night or in the early morning, subsiding within minutes. In some cases, moreover, ST-depression was observed in the ECG monitoring lead as a reciprocal manifestation of subepicardial ischaemia or due to incorrect polarity in the monitoring lead. The incidence of serious arrhythmias, AV-block and ventricular tachycardia was high (eight/12); two patients had to be DC-converted. Coronary arteriography revealed a spectrum from normal or nearly normal coronary arteries to single vessel disease. Nitroglycerin was well suited for treatment of acute attacks. Long-term treatment with calcium antagonists was effective and without serious side-effects. The follow-up time was from 8 months to 5 years (mean 2 years). It is concluded that Prinzmetal's variant angina as such is a rare disease, but that coronary artery spasm is most likely an important contributory factor in the clinical manifestations of coronary artery disease: arrhythmias, sudden death and myocardial infarction.

Natural history of combined right bundle branch block and left anterior hemiblock (bilateral bundle branch block)

One hundred fifteen patients with combined right bundle branch block (RBBB) and left anterior hemiblock (LAH) were separated into two groups depending upon whether RBBB and LAH was associated with acute myocardial infarction (group I, 32 patients) or was a chance electrocardiographic finding (group II, 83 patients). In 10 patients in group I complete heart block developed and in six patients high grade second degree atrioventricular (A-V) block developed. The incidence of serious arrhythmia was twice and mortality was three times the average for the coronary care unit (CCU). The majority of patients in group II had clinical evidence of advanced myocardial disease as manifested by congestive heart failure, healed myocardial infarction and left ventricular dyskinesia. During a cumulative observation period of 262 patient years, complete heart block developed in only two patients, whereas second-degree A-V block of sufficiently high degree to necessitate permanent cardiac pacing developed in three patients. It is concluded that (1) combined RBBB and LAH usually reflects advanced myocardial disease, (2) the clinical course is determined more by the myocardial disease than by the conduction disorder, (3) prophylactic cardiac pacing is not warranted in chronic RBBB and LAH, and (4) cardiac pacing has little impact on mortality when RBBB and LAH are associated with acute myocardial infarction.

Arrhythmias in Acute Myocardial Infarction

SUMMARY Five hundred admissions for acute myocardial infarction were studied for the incidence of arrhythmias. (The incidence of death in the entire series was 24 per cent). Three hundred and eighty-one patients representing 400 admissions demonstrated an arrhythmia of some type (80 per cent). In those with any arrhythmia, death occurred in 27 per cent; in those without arrhythmia, death occurred in 12 per cent. Serious arrhythmias, however, were accompanied by a death incidence of 47 per cent. The incidence of serious arrhythmias remained relatively constant among all age groups, while the incidence of lesser arrhythmias increased with age. With increasing age, there was a greater incidence of death in those with serious arrhythmias, despite the fact that the incidence of serious arrhythmias remained relatively constant at various ages. Among men with serious arrhythmias there was a 10 per cent higher incidence of death than among women of the same age. The incidence of death in patients having minor arrhythmias or normal rhythm was lower than that for the entire series but increased from 8 to 22 per cent with advancing age. Sex did not alter the incidence of death in this group. Ventricular tachycardia was associated with the highest incidence of death (61 per cent). Sinus bradycardia was associated with a lower incidence of death (11 per cent) than was encountered in the overall series (24 per cent). In sinus tachycardia, the incidence of death (50 per cent) was twice that for the entire series. Among the various anatomic types of infarction, lateral and multiple infarcts were associated with a higher than average incidence of death (68 per cent). Although there was no increased incidence of serious arrhythmias, the incidence of death was greater when serious arrhythmias occurred in these types of infarcts. As compared to the same arrhythmias in association with other anatomic types of infarction this may have resulted from the older age of patients having these infarcts or from the frequent association of these infarcts with altered blood flow to the S-A or A-V node. Hypertension, marked left axis deviation, diabetes mellitus, shocks, and certain other factors did not seem to influence the incidence of death in patients with the various arrhythmias. The treatment of each arrhythmia is briefly discussed, as are the indications and contraindications for the commonly used cardiac drugs.