Congenital heart disease is the most common form of birth defect, with an estimated 1-2% of live newborns afflicted by moderate or severe types [1]. 

Patients with underlying problems in the function and structure of the heart are more prone to heart rhythm problems. A heart rate that's faster than normal is called tachycardia. Tachycardia may reduce the heart's pumping ability and may require treatment [2]. Tachycardia is a heart rhythm disorder caused by abnormal electrical signals in the lower chambers of the heart. Tachycardia figure prominently among the complications encountered in the varied and diverse population of patients with congenital heart disease, and are the leading cause of morbidity and mortality [1,3]. The present study, conducted in a tertiary care center, attempted to find the prevalence and association between tachycardia and (CHD) in newborns/infants living at High Altitude.

Aims and Objectives

The aim of the study is to find the prevalence and association between tachycardia and congenital heart disease (CHD) in newborns/infants living at High Altitude.       

Type of Study

Cross-sectional observational study

Study Population

Children age between 0 to 1 year with suspected heart disease

Study Period

1 year (July 2018 to June 2019)

Setup for Study

Tertiary care set up.

Source

Outdoor and indoor services of department of pediatrics IGMC, Shimla.

Ethical Approval

his study was conducted after obtaining formal approval from the Institutional Ethical Committee of IGMC, Shimla, ensuring that all research procedures complied with established ethical standards and institutional guidelines.

Data Collection

After taking pre informed consent for this study from parents or guardians, the data related to age, gender, altitude of residence was collected. 

Confirmation of CHD

Presence of CHD was confirmed based on echo-cardiographic evidence of CHD. All children suspected to have CHD based on initial symptoms underwent echocardiography examination using echo machine model I E 33 of Philips medical system pvt. ltd. using pediatric and neonatal probe by consultant cardiologist. The 2D echo images were obtained and reviewed real time from sub costal, apical 4 chambers, parasternal long and short axis and suprasternal views supplemented with color flow imaging. Pulse and continuous wave doppler interrogation as appropriate. The presence of CHD on echocardiography was taken as the CHD present.

Operational Definition

Tachycardia: The cutoff values taken for labeling tachycardia was different for different age groups and the values taken are as follows:

• ≤ 3 months ranging 110-160/minute

• 3-6 months ranging 100-150/minute

• 6-12 months ranging 90-130/minute

Data Analysis

The data was reported as frequency and percentages for categorical variables and mean ±SD for continuous variable with normal distribution. The diagnostic performance was tested by calculating sensitivity, specificity, positive and negative predictive value using two by two tables. Two sited p value of <0.05 was taken as the statistically significant. The data was analyzed using Epi Info version7 software.

In our study there were 102 participants in total. Out of them 57 participants were ≤1 month of age i.e. 57(55.90 % of total, 29(28.4%) between 2-6 months,16(15.7%) between 7-12 months. There were 55 males and 47 females.  Most  of the participants i.e. 41(40.2%) were residents of altitude ranging between 2000-3000 meters. In the present study, tachycardia was present in 55(53.9%) out of 102 study participants (Table 1).

Table 1: Socio-Demographic Characteristics of the Study Participants

In the present study, tachycardia was present in 55(53.9%) out of 102 study participants and out of these 55 patients, 48 were diagnosed with underlying CHD. Odds ratio was 2.7 with CI (1.2-5.94), with p value of 0.019, which is significant. The sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV) of tachycardia in diagnosing CHD is 83.54 % ,56.54%, 86.84 % and 50.0% respectively (Table 2).

Table 2: Diagnostic Performance of Tachycardia in Diagnosing CHD

The population of patients with congenital heart disease (CHD) is continuously increasing. A significant portion of these young adults will suffer from tachycardia due to the underlying congenital heart defect [4].

Tachycardia is an arrhythmia (abnormal heart rhythm) that is quite common in children. It can occur in children with congenital heart disease that affect the heart’s electrical system [5].

The present hospital based cross-sectional observational study was conducted among patients aged 0-1 year for a period of one year from July 2018 to June 2019. The primary aim of the study was to identify clinical signs/symptoms that best predicts CHD in newborns/infants. In the current study, 102 patients coming to pediatric OPD or indoor were included on the basis of criteria of suspicion and clinical parameters to detect CHD. 

In the present study, 79(77.5%) patients (46 male and 33 female) were detected to have underlying congenital heart disease out of total 102 patients. Maximum 57(55.9%) patients were of ≤1 month of age group and among them 44 (77.19%) had underlying congenital heart disease. So therefore, it is essential to recognize congenital heart disease in the early stages as the deterioration is sudden and, most of the children with complex heart disease die at presentation or before any surgical intervention is made [6]. Between 2-6 months, 29 (28.4%) patients were suspected of CHD, out of which 21(72.41%) had underlying CHD. Between 7-12 months age group, 16(15.7%) patients were suspected of CHD out of which, 14(87.5%) had underlying CHD.

Among 79 study participants having underlying congenital heart disease, 48(60.8%) were those having tachycardia and 31(39.2%) had normal heart rate. Odd ratio was 2.7 with 95% CI (1.2-5.94), with a statistically significant p value of 0.019. The sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV) of tachycardia in diagnosing CHD is 83.54 % ,56.54%, 86.84 % and 50.0% respectively. So, tachycardia can be considered as an important tool in screening of CHD.

Many different conditions can cause tachycardia. It's important to get a prompt, accurate diagnosis and appropriate care. Consultation to doctor is necessary if the child has any problems with the heartbeat like tachycardia [6].

There were high sensitivity and positive predictive value (PPV) of tachycardia in diagnosing CHD.  So, tachycardia can be considered as a significant parameter in screening of CHD in children age less than one year living at high altitude Considering this, it would be necessary to screen all children presenting with tachycardia in clinical practice.

1. Khairy, P. and S. Balaji. “Cardiac arrhythmias in congenital heart diseases.” Indian Pacing and Electrophysiology Journal, vol. 9, no. 6, 2009, pp. 299–317.

2. “Arrhythmias and congenital defects.” American Heart Association, 18 June 2021, https://www.heart.org/en/health-topics/congenital-heart-defects/the-impact-of-congenital-heart-defects/arrhythmias-and-congenital-defects.

3. “Ventricular tachycardia: Symptoms and causes.” Mayo Clinic, 21 June 2021, https://www.mayoclinic.org/diseases-conditions/ventricular-tachycardia/symptoms-causes/syc-20355138.

4. “Europace article.” Europace, 22 June 2021, https://academic.oup.com/europace/article/20/11/1719/4944677.

5. “Ventricular tachycardia.” C.S. Mott Children’s Hospital, 22 June 2021, https://www.mottchildren.org/conditions-treatments/ped-heart/conditions/ventricular-tachycardia.

6. Gupta, H. et al. “Pulse Oximetry for the Early Detection of Congenital Heart Diseases.” International Journal of Medical Research Professionals, vol. 3, no. 4, 2017, pp. 227–231.