Ventricular tachycardia — structured written assessment

SAQ 1 (10 marks)

Practice scenario. A 64-year-old man with a previous anterior myocardial infarction presents with palpitations. The ECG shows a regular wide QRS tachycardia at 165 b.p.m. He is alert, blood pressure 116/70 mmHg, with no chest pain or heart failure; echocardiography last year showed an LVEF of 45%, and his sinus-rhythm ECG shows no conduction disease. Troponin is not raised and renal function is normal. ^[1]

1. What is the default diagnosis, and why does it matter? (2)
2. List four of the 2019 ESC SVT guideline Table 9 criteria that suggest VT rather than SVT in a wide complex tachycardia. (4)
3. The tachycardia is sustained monomorphic VT. Outline the 2022 ESC options for acute termination, with class and level. (4) ^{[1] [2]}

Model answers

1. VT until proven otherwise. Wide QRS tachycardias can be VT, SVT with BBB aberration, or antegrade conduction over an accessory pathway, in reported proportions of 80, 15 and 5%. Misdiagnosis and drugs usually used for SVT can harm a patient in VT.^[2]
2. Any four of the criteria in Table 9 of the 2019 ESC SVT guideline: AV dissociation (ventricular rate above atrial rate); fusion or capture beats (QRS morphology different from that of the tachycardia); chest lead negative concordance (all precordial leads negative); absence of RS in the precordial leads, or RS above 100 ms in any lead (RS: beginning of R to deepest part of S); in aVR, an initial R wave, an initial R or Q wave above 40 ms, or a notch in a predominantly negative complex; QRS axis −90 to ±180° (with RBBB or LBBB morphology); R wave peak time of 50 ms or more in lead II; RBBB morphology with, in V1, a monophasic R, Rsr′, biphasic qR, broad R above 40 ms or a double-peaked R with the left peak taller ('rabbit ear'), or in V6 an R:S ratio below 1 (rS, QS); LBBB morphology with, in V1, a broad R wave, a slurred or notched-down stroke of the S wave or a delayed S nadir, or in V6 a Q or QS wave.^[2]
3. DC cardioversion is first-line for tolerated SMVT provided that the anaesthetic/sedation risk is low (Class I, level C). For haemodynamically tolerated SMVT with known or suspected SHD, intravenous procainamide should be considered (Class IIa, level B). For haemodynamically tolerated SMVT in the absence of an established diagnosis, intravenous amiodarone may be considered (Class IIb, level B). Intravenous verapamil is not recommended in broad QRS tachycardia of unknown mechanism (Class III, level B); once SMVT is established after infarction, verapamil's Class I rows do not apply, because both are for idiopathic VT, which is not associated with SHD or a genetic arrhythmic syndrome. Intravenous procainamide should not be used in severe heart failure, acute MI or end-stage renal disease, and ESC Table 8 contraindications include severe LV dysfunction and hypotension; he has none of these.^[1]

SAQ 2 (10 marks)

Practice scenario. A different patient, a 69-year-old man with ischaemic cardiomyopathy, received an ICD after haemodynamically not-tolerated VT with no reversible cause. Eighteen months later, on amiodarone and a beta-blocker, he has three separate episodes of monomorphic VT within 12 hours, each more than 5 min apart and each terminated by an appropriate ICD shock. ^[1]

1. Which 2022 ESC recommendation supported his secondary prevention ICD, and what does the meta-analysis of the secondary prevention trials show? (3)
2. Define electrical storm and list the ESC 2022 Class I measures in the Recommendation Table 9 electrical storm group for this presentation. (4)
3. The storm settles, but SMVT with shocks recurs despite chronic amiodarone. What does the ESC recommend, and what evidence supports it? (3) ^{[1] [6] [10] [11]}

Model answers

1. An ICD is recommended in patients with documented VF or haemodynamically not-tolerated VT in the absence of reversible causes (Class I, level A).^[1] In the AVID, CASH and CIDS meta-analysis, the ICD reduced death from any cause (HR 0.72) and arrhythmic death (HR 0.50) compared with amiodarone, extending survival by a mean of 4.4 months over 6 years.^[6]
2. Electrical storm is VA that occurs 3 or more times within 24 h (separated by at least 5 min), each requiring termination by an intervention. Class I measures in the electrical storm group of Recommendation Table 9: mild to moderate sedation, to alleviate psychological distress and reduce sympathetic tone (level C); beta-blockers, non-selective preferred, with intravenous amiodarone in SHD unless contraindicated (level B); and catheter ablation in incessant VT or electrical storm due to SMVT refractory to AADs (level B); the two TdP rows of that group do not apply to monomorphic VT. Other Class I rows outside this group also apply, for example investigation for reversible causes (e.g. electrolyte imbalances, ischaemia, hypoxaemia, fever) in patients with VA (Recommendation Table 8, level C), optimisation of ICD programming to avoid inappropriate and unnecessary therapies and to reduce mortality (Recommendation Table 16, level A), and assessment of psychological status and treatment of distress in ICD patients (Recommendation Table 18, level C).^[1]
3. In CAD with recurrent, symptomatic SMVT, or ICD shocks for SMVT, despite chronic amiodarone, catheter ablation is recommended in preference to escalating AAD therapy (Class I, level B).^[1] In VANISH, death, VT storm or appropriate ICD shock occurred in 59.1% with ablation versus 68.5% with escalated antiarrhythmic drug therapy (HR 0.72), with no significant mortality difference.^[10] Beyond this row, VANISH2 (2025) found that, in ischaemic cardiomyopathy with VT, an initial strategy of catheter ablation led to a lower composite risk than AAD therapy (50.7% vs 60.6%; HR 0.75).^[11]