Broad-complex tachycardia

Diagnosis: The regular broad-complex tachycardia in the patient with the previous myocardial infarction (the structural heart disease) is the ventricular tachycardia until proven otherwise. This patient is borderline (the systolic 100, the dyspnoea) — assess for the instability.^[3]

Assessment: ABCDE, the oxygen, the IV access, the continuous monitoring, the defibrillator at the bedside. The 12-lead ECG during the tachycardia (and a rhythm strip). The bloods: the electrolytes (the potassium, the magnesium, the calcium), the troponin, the magnesium, the digoxin level, the toxicology. The search for the reversible cause (the ischaemia, the electrolyte, the sepsis).^[3]

Stability assessment: The instability is the shock or the hypotension (the systolic below 90), the ischaemic chest pain, the acute heart failure, the altered consciousness. This patient is borderline (the systolic 100, the dyspnoea) — he is treated as the unstable if he deteriorates.^[3]

Management — if unstable or borderline-deteriorating: The synchronised DC cardioversion (120 to 150 joules biphasic, escalating), with the sedation and the analgesia.^[3]

Management — if stable: The IV amiodarone (the 300 milligrams over the 20 to 60 minutes, then the infusion of 900 milligrams over 24 hours). The alternatives are the procainamide and the lidocaine. The cardinal rule: the broad-complex tachycardia of the uncertain origin is treated AS the ventricular tachycardia — the verapamil is never given, and the adenosine is never a substitute for treating as VT (at most a monitored diagnostic probe in the genuinely indeterminate trace). The electrolytes are corrected.^[3]

Cardinal rule reinforced: Never give verapamil to a broad-complex tachycardia of uncertain cause — verapamil in VT precipitates profound hypotension and VF; adenosine is not a treatment for presumed VT.^[3]

Disposition: The coronary care or the intensive care, the continuous monitoring, the cardiology referral for the definitive management (the implantable cardioverter-defibrillator if the VT is sustained and structural).^[3]