Prolonged QTc and Prevention of Torsades de Pointes Clinical Pathway — Inpatient

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Inpatient with Prolonged QTc on 12-Lead Electrocardiogram
This pathway provides guidance for consultation, management,
and telemetry monitoring for inpatients with QTc prolongation

FLOC Assessment

Review:
- Vital signs, physical exam
- Risk Factors/Conditions Associated with Prolonged QT
- Current medications, recent laboratory values
- Completed 12 lead ECG, including other abnormal findings of importance
Initiate clinical actions based on automated ECG reading
(machine interpretation) pending confirmation by Cardiac EP service

QTc ≥ 470-499 ms
Contact Cardiology Consult service for guidance

QTc ≥ 500 ms
FLOC consult PHL Cards EP service for expeditious confirmation of ECG findings, specifically QTc interval

Hemodynamically Stable
without ventricular
arrhythmia

Hemodynamically Stable
with non-sustained ventricular arrhythmia

Non-sustained ventricular tachycardia:
- ≥ 3 consecutive ventricular beats lasting < 30 sec
Frequent ventricular ectopy:
- > 2 PVCs per 10 sec
- > 30 per hour

Hemodynamically Unstable
with sustained ventricular tachycardia/torsades de pointes

Call Critical Assessment Team (CAT)
Consult PHL Cards EP service immediately

Call Code Response
Consider magnesium sulfate IV
- 50 mg/kg/dose
  Max dose 2 g/dose
Consult PHL Cards EP service immediately
Transfer to ICU

Initiate Telemetry/Supplemental Arrhythmia Monitoring

Telemetry
- Real-time alarm response
- Cardiac Center (CICU, CCU, CPRU, ITCU)

Supplemental Arrhythmia Monitoring
- Intermittent review of non-audible alarms
- Non-Cardiac Center (N/IICU, PICU, PCU)

Medical Management and Monitoring
Risk Factors/Conditions for Prolonged QTc	Correct modifiable risk factors Electrolyte goals: Potassium ≥ 4 mmol/L Magnesium ≥ 2 mg/dL Ionized Calcium ≥ 1.2 mmol/L Correct metabolic acidosis Remove QTc prolonging medications as feasible Consult Clinical Pharmacy as needed Manage medical conditions that increase risk
Monitoring	If QTc ≥ 500 ms: Initiate telemetry/supplemental arrhythmia monitoring Add Prolonged QT Interval to problem list Suggested ICD 10 Codes for Problem List Daily ECG after correction of modifiable risk factors or per EP recommendations until QTc remains stable < 500 ms without new risk factors or until steady state of a QTc prolonging medications is expected to have been reached If QTc ≥ 470-499 ms: Repeat ECG after correcting modifiable risk factors Review with Cardiology Consult Service: Further guidance if QTc not improved after medical management Timing of repeat ECGs Follow-up recommendations for all children

Medical Management and Monitoring

Risk Factors/Conditions for Prolonged QTc

Correct modifiable risk factors
Electrolyte goals:
- Potassium ≥ 4 mmol/L
- Magnesium ≥ 2 mg/dL
- Ionized Calcium ≥ 1.2 mmol/L
Correct metabolic acidosis
Remove QTc prolonging medications as feasible
Consult Clinical Pharmacy as needed
Manage medical conditions that increase risk

Monitoring

If QTc ≥ 500 ms:
- Initiate telemetry/supplemental arrhythmia monitoring
- Add Prolonged QT Interval to problem list
  - Suggested ICD 10 Codes for Problem List
- Daily ECG after correction of modifiable risk factors or per EP recommendations until QTc remains stable < 500 ms without new risk factors or until steady state of a QTc prolonging medications is expected to have been reached
If QTc ≥ 470-499 ms:
- Repeat ECG after correcting modifiable risk factors
- Review with Cardiology Consult Service:
  - Further guidance if QTc not improved after medical management
  - Timing of repeat ECGs
  - Follow-up recommendations for all children

Posted: March 2023
Authors: C. Srinivasan, MD; N. Bernard, RN; H. Wolfe, MD; H. Stinson, MD; J. Freedman, MD; V. Vetter, MD

Evidence

CHOP Programs

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The clinical pathways are based upon publicly available medical evidence and/or a consensus of medical practitioners at The Children’s Hospital of Philadelphia (“CHOP”) and are current at the time of publication. These clinical pathways are intended to be a guide for practitioners and may need to be adapted for each specific patient based on the practitioner’s professional judgment, consideration of any unique circumstances, the needs of each patient and their family, and/or the availability of various resources at the health care institution where the patient is located.

Accordingly, these clinical pathways are not intended to constitute medical advice or treatment, or to create a doctor-patient relationship between/among The Children’s Hospital of Philadelphia (“CHOP”), its physicians and the individual patients in question. CHOP does not represent or warrant that the clinical pathways are in every respect accurate or complete, or that one or more of them apply to a particular patient or medical condition. CHOP is not responsible for any errors or omissions in the clinical pathways, or for any outcomes a patient might experience where a clinician consulted one or more such pathways in connection with providing care for that patient.

Inpatient Clinical Pathway for Child with Prolonged QTc and Prevention of Torsades de Pointes

Evidence

CHOP Programs

Inpatient Clinical Pathway for Child with Prolonged QTc
and Prevention of Torsades de Pointes