ecgsweep

Monomorphic VT

caution
Lead II
25 mm/s10 mm/mV
HR72bpm
RR833ms
QT358ms
Type

Three or more consecutive ventricular beats at ≥ 100 bpm, self-terminating within 30 seconds.

Updated

On the trace

Read the strip in the order it happens.

Try each step, then check it.
  1. Start in sinus rhythm.
    Show Narrow complexes, each with its P wave.
  2. Count the wide beats.
    Show A burst of three or more identical wide complexes at 100 bpm or faster interrupts the sinus rhythm.
  3. Watch it stop.
    Show The run ends on its own, abruptly, and a narrow sinus beat follows: the normal conduction system has the ventricles back.

How to recognise it

FeatureValueNotes
Run length≥ 3 beatsTwo in a row is a PVC couplet, not VT.
Duration< 30 secondsStops on its own. Longer, or needing termination, is sustained VT.
Rate during burst≥ 100 bpmSlower is accelerated idioventricular rhythm.
MorphologyUniformThe same shape throughout the run; a changing shape is polymorphic.
Baseline rhythmSinusThe runs interrupt an otherwise normal rhythm.

The strip

Thirty seconds of sinus rhythm with runs of non-sustained VT in lead II, drawn by the simulator. Work through the steps above on it, in the order it happens.

Management

1

Assess the substrate

The run is already over; what matters is the heart it came from. Echocardiography at minimum: a reduced ejection fraction, a regional wall motion abnormality or hypertrophy each change the risk. After a prior infarction or with unexplained LV dysfunction, an electrophysiology study may be needed.

2

Stratify by structure

In a structurally normal heart NSVT is usually benign: reassure and remove reversible triggers (electrolytes, stimulants, ischaemia). With structural disease it marks a higher risk of sustained VT and sudden death, and the threshold for an ICD is lower.

Differential

Monomorphic Ventricular Tachycardia

The same arrhythmia that does not stop: over 30 seconds, or needing termination sooner. Management moves from assessment to immediate treatment.

Premature Ventricular Contractions (PVCs)

One or two wide beats is PVC territory; three or more at 100 bpm or faster is a VT run. Same ectopic mechanism, counted.

The full pictureMonomorphic Ventricular TachycardiaMechanism, causes and management are covered in the base rhythm.

References

  1. 2022 ESC Guidelines for the management of patients with ventricular arrhythmias and the prevention of sudden cardiac death — European Heart Journal, 2022