الفهرس 
IntroductionOnly 14 pages are availabe for public view
 |  | from | 91 |  |  |
| | | from | 91 | | |
Abstract
Bradycardia is defined as a heart rate below the lowest normal value for age.
Bradycardia most commonly manifests as sinus bradycardia, junctional bradycardia, or atrioventricular (AV) block. As a result of several different etiologies, it may occur in an entirely structurally normal heart or in association with concomitant congenital heart disease.
The objective of this study is to to evaluate the pattern of bradycardia in children at Sohag University Hospital. Using a prospective cohort observational study design, this study was conducted in our PICU, ER and pediatric arrhythmia clinic on all infants aging from one day till 18 years of age who was admitted in one year period from May 2020 till April 2021 to PICU, ER and pediatric arrhythmia clinic in Sohag University Hospital. These units provide specialized care to critically ill infants.
Inclusion criteria included any child from one day old up to 18 years old who has bradycardia, while Exclusion criteria included Predeath bradycardia.
After patient stabilization medical history was collected from infant’s relatives and complete clinical examination was conducted. Serum electrolytes, ECG and echocardiography were done for all patients with bradycardia.
12 leads ECG was done to any infant with bradycardia. Interpretation of every ECG paper was done using specific centile tables for normal values of ECG waves and intervals according to age.
Emergency and maintenance therapy for bradycardia was performed according to standard protocols.
The overall prevalence of bradycardia was 61 Patients included in this study. 53% of them were boys and 47% are girls.
In our study sinus bradycardia was the main type of bradycardia in all units.
28% had abnormal echocardiography.
Syncopal attacks were the presenting symptom in 8.2% 0f cases.
8.2% was diagnosed during routine examination.
Chest pain and follow up of beta blocker therapy were the presentation in 6.6% of patients.
Gastroenteritis and hypokalemia were present in 5% of cases.
Signs of shock were present in 3.3%.
Renal failure, chronic Nephrotic syndrome, Digitalis toxicity, Covid – 19 infection and Hypothyroidism were evident in 1.6% for each.
Heart rate of the studied patients ranged from 44 to 94 beat/minute with mean 69.44 beat/minute.
70.5%of them had sinus bradycardia, 3.3% had 1st and 2nd degree heart block, 27.9% had CHB, about 10% of patients had long QTc interval with sinus bradycardia and 1.6% had ECG changes of ALCAPA with sinus bradycardia.
heart block was predominant in 8 children with CHD pre and post-operative (13% of bradycardia cases) and 2 patients with congenital complete heart block (3.3% of bradycardia cases), sinus bradycardia was present in 2 post-operative cases for CHD, in 2 patients with cardiomyopathy and in 2 patients with mild left ventricular dilatation (3.3% of bradycardia cases) for each.
Hypocalcaemia was the cause of bradycardia in 16.4% of cases of sinus bradycardia as improvement of bradycardia occurred after treatment with vitamin D and calcium supplementation.one case with hypocalcaemia needed endocrinological consultation. Electrolyte disturbances were the cause of bradycardia in 5% of cases. Sinus bradycardia was due to effect of drugs (4 patients on b- blocker therapy and 1 patient with digitalis toxicity) and 6 patients with long QT syndrome Sinus bradycardia was present in 13.1% of cases late after cardiac surgery mostly due to sick sinus syndrome.
Sinus bradycardia was present in one 11 years old patient (2.3% of sinus bradycardia cases) due to CPVT diagnosed by stress ECG, in one patient 1.5 years old presented by marked sinus bradycardia and shock diagnosed to have hypothyroidism he needed inotropic support and improved on thyroid replacement hormone therapy and in one patient 9 years old with fever diagnosed to have Covid-19 infection, he had marked sinus bradycardia, he was shocked and needed inotropic support till sinus bradycardia improved.
Holter monitoring was used in 17 patients. Heart block was confirmed in 8 patients. Sinus bradycardia was confirmed in one post-operative cardiac patients and in 5 patients with syncope. One patient with syncope had sinus bradycardia on his ECG showed polymorphic ventricular tachycardia in his Holter study.
Treatment of sinus bradycardia in both PICU and ER was by treatment of the cause.
72% of patients received vitamin D and calcium supplementation. Pacemaker implantation was needed in only 1 patient (1.6%) with late post cardiac surgery bradycardia. Beta blocker therapy was indicated in 7 patients (6 patients with long QT syndrome and one patient with CPVT). 2 patients (3.3%) needed inotropic support. Correction of electrolytes improved bradycardia in 5% of patients. 0ne patient 3 years old with restrictive cardiomyopathy was on treatment for heart failure. One patient with ALCAPA referred for surgery. Thyroid replacement therapy corrected bradycardia in one patient with hypothyroidism. Inotropic support needed in 7 patients as One patient with Covid-19 and 6 patients (4 on beta blocker therapy and 2 post ASD patch closure patients).
Conclusions:
1- Bradycardia is defined as a heart rate below the lowest normal value for age. Two main physiological mechanisms are sinus bradycardia and AV block.
2- Bradycardia among children can be caused by different conditions rather than cardiac causes, e.g. hypocalcaemia and medications as beta blockers and digoxin.
3- Patients with severe bradycardia have insufficient cardiac output and poor peripheral perfusion. They require immediate medical attention. Acute management includes assessing and restoring the cardio-respiratory state and identifying reversible causes of bradycardia. Medical management includes administration of epinephrine, atropine, and/or cardiac pacing.
4- The American College of Cardiology/American Heart Association/Heart Rhythm Society published guidelines in 2008 for the use of permanent pacing in children, adolescents, and patients including those with sinus bradycardia and heart block.
5- Echocardiography flowed by ECG and Holter ECG have an important role in evaluation of children with bradycardia.
6- Early diagnosis and appropriate management are critical in many cases in order to prevent sudden death.
Recommendations:
1- Further longitudinal studies with large sample size in pediatric age are needed to evaluate bradycardia diagnosis and management.
2- Holter ECG and bedside echocardiography can be helpful in monitoring and evaluation of bradycardia in pediatrics.
3- Electrolyte disturbance as hypocalcaemia, hypokalemia need close monitoring and assessment of cardiac functions in pediatric.