Ventricular Tachycardia Management in Newborn with Congenital Cardiac and Extracardiac Diseases: A Rare Case Report.

Farruggio S¹, Khorgami MR², Zanai R¹, Calvaruso D¹, Ortiz Ruiz DA¹, Agati S¹, Di Mambro C¹, Caruso E^1*
 

1. Department of Pediatric Cardiology, Mediterranean Pediatric Cardiology Center "Bambin Gesù", San Vincenzo Hospital, Taormina (ME), Italy.
 

2. Cardiac Electrophysiology Research Center, Rajaie Cardiovascular Medical and Research Center, Iran University of Medical Sciences, Tehran, Iran

*Corresponding Author: Dr. Elio Caruso, Department of Pediatric Cardiology, Mediterranean Pediatric Cardiology Center "Bambin Gesù", San Vincenzo Hospital Contrada Sirina 98039 Taormina (ME), Italy.
 

Received Date:  November 13, 2020

Publication Date: December 01, 2020

DOI: 10.1027/marcy.2020.0122
 

Abstract
Ventricular tachycardia in newborns and infants is an extremely rare arrhythmia and few reports have been described. Acute management and prompt treatment is crucial to avoid tachycardiomyopathy, haemodynamic instability and sudden death. We describe a very rare case of ventricular tachycardia treated with amiodarone in a two-months-old female infant with multiple congenital cardiac and extracardiac diseases and discuss its diagnosis and management.

Keywords: Ventricular tachycardia, ventricular septal defect, atrial septal defect, congenital heart disease

Case Report

We report a very rare case of ventricular tachycardia (VT) in a two-month-old female infant, with congenital heart disease (CHD), vascular and anorectal malformations.

She was born full-term by cesarean section at 38 weeks of gestational age, from unrelated parents with a family history negative for CHD. At birth she presented good clinical condition, APGAR of 9 at 1’ and 5’ minutes after delivery, normal blood pressure, her body weight at birth was 3.040 kg with 93% of O2 blood saturation (O2 BS), and physical examination showed a grade 3/6 holosystolic murmur and anorectal atresia.

Echocardiogram showed atrial septal defect ostium secundum type shunting left-to-right (Fig. 1 A), patent ductus arteriosus (PDA) shunting aorta-to-pulmonary artery, left-superior caval vein (LSCV) draining directly in the left atrium (Fig. 1 D) with unroofed coronary sinus, and subaortic perimembranous ventricular septal defect (VSD) wide about 5 mm (Fig. 1 B-C) shunting mainly left-to-right (Fig. 1 C).

The patient after one day from the birth underwent to colostomy surgery in another hospital and about after two months was referred to our intensive care unit (ICU) for dyspnea and frequent premature ventricular contractions (PVCs) during hospitalization in the other center. Baseline ECG made in the other hospital showed a sinus rhythm (SR) with a heart rate (HR) of 150 beats per minute (bpm), high P-wave voltage (> 0.25 mV in the limb leads), normal PR interval (120 ms) and cardiac axis, increased QRS voltage in precordial leads, nonspecific ST-T wave changes. ECG monitor in ICU showed a suspected supraventricular tachycardia (SVT) with narrow QRS, then a first therapeutic approach was done with iv adenosine bolus at the dosage of 0,1 mg/kg increasing dosage to 0,2 mg/kg until 0,4 mg/kg without resolution of arrhythmia. The patient was pale, dyspnoic with good blood pressure. A transesophageal electrophysiological study was performed, after informed consent obtained from parents, on the doubt of an SVT refractory to adenosine. Atrial stimulation started by 10 mA for 10 ms with an HR faster than the baseline and adjusted according to the stimulus threshold (Esodik 6 fr quadripolar catheters (FIAB programmable cardiac stimulator 8817) was attempted in ICU, without sedation, showing atrial capture with high rate overdrive without interrupting the arrhythmia. Esophageal atrial pacing was done with a shorter cycle length than RR interval, as a result, we observed the QRS duration became narrower with overdrive pacing, later, after stopped atrial pacing, we expected the QRS duration became wider due to the behavior of the cardiac conduction system with atrial pacing. Therefore, after the last paced beat, the ventricular arrhythmia reappears with the same cycle length (Fig. 2 B). After these quick attempts in our ICU, 12 lead ECG showed tachyarrhythmia with a QRS complex wide 0,08 ms (high age limit) with atrial retroconduction and HR of 280 bpm (Fig. 2 A). A few minutes later ECG showed wide QRS tachycardia alternated to SR and ventricular bigeminy (Fig. 2 C). A differential finding between SVT and VT is the similarity of bigeminy PVCs during sinus rhythm with QRS morphology during tachycardia (Fig. 2 A-C). Therefore, the final diagnosis was VT for the followed findings: VA dissociation (Fig. 3) with ventricular rates exceeding atrial rates (AV ratio < 1:1), QRS duration at the high upper limit for age (0,08 sec) with inferior axis configuration, and morphology of QRS complex suggested a monomorphic VT originating from right ventricular outflow tract (RVOT-VT) [1].

Despite an iv bolus of amiodarone at dosage of 5 mg/kg in 40 minutes, the infant presented further VT episodes treated with sulfate magnesium bolus of 150 mg iv restoring SR (Fig. 2 D). Amiodarone was continued at a maintenance dosage of 15 mg/kg/day iv and then 8 mg/kg/day per os, to maintain SR. No side effects or arrhythmic events were reported. After the resolution of arrhythmia, the patient showed a worsening of saturation (80% O2 BS), and a cardiac catheterism was performed confirming the presence of LSVC draining in the left atrial chamber and pointing out the presence of right-pulmonary arteriovenous malformations treated through the positioning of plugs. One month later Heart Team decided on definitive surgery placing a patch to close the VSD, tunneling LSCV in the right atrium, and closing PDA.

Figures:

Figure 1 – A. Subcostal view shows atrial septal defect ostium secundum type (arrow). 

                B. Parasternal short axis shows a wide subaortic perimembranosous VSD shunting left-to-right. 

                C. Apical five-chamber view shows VSD’s dimension of 5,4 mm (arrow).

                 D. Suprasternal view shows pulmonary veins draining in LA and LSCV draining directly in LA with unroofed coronary sinus. AO aorta, LA left atrium, LSCV left superior caval vein, LV left ventricle, PA pulmonary artery, RA right atrium, RV right ventricle

Figure 2 – A. 12 lead ECG shows VT with atrial retroconduction at HR of 200 bpm.

               B. Transesophageal atrial pacing shows high rate overdrive without interrupting the VT.

               C. Ventricular bigeminy.

               D. Sinus rhythm at 160 bpm, high P voltage, right axis configuration, normal intraventricular conduction, QTc 440 ms.

Figure 3. ECG shows tachycardia with wide QRS complex, not clearly evident retroconducted P waves, but the first red lines showed AV dissociation and allowed us to do diagnosis of VT; the subsequent red lines indicate P waves followed by QRS complexes as resumption of sinus rhythm at 130 bpm.

Discussion

VT is a malignant arrhythmia that can induce tachycardiomyopathy, hemodynamic instability, and sudden death without any prompt treatment. It is rarely observed in children and accounts for an incidence of 1.1 episodes/100 000 childhood years [2].

Idiopathic VT is observed in the heart without anomalies associated and is the most common type of VT in pediatric [3]. VT in heart diseases occurs in CHD like double outlet right ventricle, transposition of great arteries and VSD [4], cardiomyopathy, cardiac tumor, primarily hamartomas [5], and channelopathy. In patients underlying heart disease, VT has the highest mortality rate [2-3], particularly for patients with hypertrophic or restrictive cardiomyopathy.

In newborns, VT is a very rare arrhythmia and few reports have been described. Van Hare et al. in 1991 reported fourteen neonates presented VT or accelerated ventricular rhythm, the most presented structural normal heart and accelerated ventricular rhythm which was a typical conduction disorder of immediate postnatal period with a benign prognosis which disappeared early with development [6].

Caruso et al described a rare case of left ventricular myocardial infarction and RVOT - VT in a full-term male newborn presented severe asphyxia due to maternal anesthesia and prolonged labor during caesarean delivery [7].

The most common VT encountered in children has origin from foci located in RVOT. The main morphological findings are the presence of a wide QRS with a left bundle branch block pattern and an inferior axis configuration. Although these automatic foci are sensitive to autonomic tone and maybe catecholamine and exercise sensitive [8], it is known that the clinical presentation of RVOT-VT can be mutable. Insights into the cellular mechanism of outflow tract VT allowed to understand general principles about its nature: high HR, through overdrive pacing or catecholamine infusion, induces its initiation, and its termination is dependent on either direct blockade of the dihydropyridine receptor by calcium channel blockers or agents or maneuvers that lower cyclic adenosine monophosphate (cAMP) levels, like Adenosine or vagal maneuvers. The defining characteristics and responses observed in this arrhythmia are unique to outflow tract tachycardia and differentiate it from all other ventricular arrhythmias. Adenosine’s antiarrhythmic properties on ventricular myocardium are due primarily to its antagonism of the stimulatory effects of beta-adrenergic activation on intracellular calcium [9].

Arrhythmias are the most life-threatening complications of VSDs and from 16% to 31% of patients with VSD have serious arrhythmias, including VT, ventricular couplets, and multiform PVCs. Sudden death in Wolfe et al’s series occurred in 4.2% of cases caused by higher mean pulmonary artery pressure, myocardial hypertrophy, and cardiomegaly, which are known to be arrhythmogenic [11-13].

In our case, VT originated from the right ventricular outflow tract (RVOT-VT) and certainly, other triggers contributed to induce ventricular arrhythmia like ventricular overload and high pulmonary overflow due to VSD.

When VT is secondary to cardiac disease, it can be malignant, with a high and variable heart rate, and a high risk of heart failure [14]. Our patient despite the complex extracardiac and cardiac diseases and the acute malignant arrhythmia successfully treated with sulfate magnesium and amiodarone, was discharged without any complications. We used amiodarone as is the drug of choice in case of a reduction in ejection fraction and its efficacy for VT was widely demonstrated, especially when VT is related to CHD. Amiodarone is more rapidly metabolized in pediatric patients and the incidence of side effects is lower than that observed in adults [14-15]. It is an effective and safe drug in young patients with life-threatening arrhythmias, doesn’t impair growth and severe side effects are very rare as indicate in a long-term follow-up reported by Guccione et al [16].

Conclusions

VT is a malignant arrhythmia rarely reported in pediatrics and the appropriate management in infants underlying heart malformations is highly dependent on the specific diagnosis and associate with significantly high morbidity and mortality.

This case report could be helpful for pediatric cardiologists who have to manage complex arrhythmias borderline between VT and SVT associated with CHD. It’s mandatory to do 12 ECG leads in infants with tachycardia and never trust ECG monitor trace because differential diagnosis between SVT and VT could be challenging in some cases. Amiodarone is a potent antiarrhythmic drug that proved to be effective in life-threatening arrhythmias and safe with a low rate of side effects in pediatric population.

Disclosures
None

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Volume 1 Issue 4 December 2020
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