Baseline Cardiac Assessment Prior to Initiating Stimulant Therapy for ADHD

Required Pre‑Treatment Cardiac Evaluation

Obtain a detailed personal cardiac history that specifically asks about syncope, chest pain, palpitations, and exercise intolerance. [@1]
Include inquiry about prior cardiac diagnoses, seizures, and any history of arrhythmias in the personal history. [@1]
Collect a focused family cardiac history for sudden unexplained death before age 50, early cardiovascular disease, Wolff‑Parkinson‑White syndrome, hypertrophic cardiomyopathy, long‑QT syndrome, and other inherited arrhythmia syndromes. [@2]
Record baseline vital signs (heart rate and blood pressure) for every patient, regardless of age. [@3]

Perform a baseline ECG when the patient has a personal history of syncope, near‑syncope, or unexplained seizures. [@2]
Perform a baseline ECG when the family history includes sudden cardiac death, long‑QT syndrome, Wolff‑Parkinson‑White syndrome, or hypertrophic cardiomyopathy. [@2]
Perform a baseline ECG if a structural heart disease is known or a cardiac murmur is detected on examination. [@2]
Perform a baseline ECG for symptoms suggestive of arrhythmia (recurrent palpitations with syncope, chest pain during palpitations, dyspnea). [@2]
Perform a baseline ECG in patients older than 50 years, as the risk of sudden cardiac death rises roughly ten‑fold after this age. [@2]
Perform a baseline ECG when the patient is taking concomitant QT‑prolonging medications. [@2]

Upper‑limit normal QTc values: > 450 ms in men and > 460 ms in women are considered prolonged. [@4] [@5]
QTc < 450 ms (men) or < 460 ms (women): Stimulant therapy may be initiated safely. [@5]
Grey‑zone QTc (450‑500 ms in men; 460‑500 ms in women): Requires comprehensive assessment, including detailed family history, cascade ECG screening of relatives, 24‑hour ECG monitoring, exercise testing, and cardiology referral before starting stimulants. [@6]
QTc ≥ 500 ms: Represents unequivocal long‑QT syndrome and is an absolute contraindication to stimulant therapy; stimulants must be withheld, cardiology referral and genetic evaluation are advised, and non‑stimulant ADHD medications (e.g., atomoxetine, guanfacine, clonidine) should be considered. [@7]

If QTc prolongs to > 500 ms or rises by ≥ 60 ms from baseline, immediately discontinue the stimulant, correct electrolyte abnormalities (e.g., hypokalemia, hypomagnesemia), and review any QT‑prolonging drugs. [@7]
After QTc normalizes, the stimulant may be restarted at a reduced dose. [@4]
Increase the frequency of ECG monitoring if therapy is continued after a QTc abnormality. [@4]
At each follow‑up visit, measure heart rate and blood pressure; stimulants typically raise heart rate by 1‑2 bpm and systolic/diastolic pressure by 1‑4 mm Hg. [@1]
Approximately 5‑15 % of patients experience larger hemodynamic increases that may require clinical intervention. [@1]

Do not order routine ECGs for all patients; employ risk‑stratified screening based on history and physical examination. [@2]
Do not assume that previously “controlled” cardiac conditions automatically permit stimulant use without reassessment; sympathomimetic effects can precipitate decompensation. [@1]
Do not ignore grey‑zone QTc values; they mandate a thorough cardiac work‑up before proceeding. [@6]
Do not omit a detailed family cardiac history, as inherited arrhythmia syndromes may be uncovered only through relatives. [@2]
Do not continue stimulant therapy if QTc exceeds 500 ms during treatment, given the high risk for torsades de pointes. [@7]