ECG criteria
- Rhythm: sinus rhythm or atrial fibrillation (especially in mitral stenosis) — evaluate in leads II and V1
- P mitrale in mitral valve disease: P wave in lead II is wider than 120 ms, notched (M-shaped); in V1, a terminal negative phase with a depth of ≥1 mm and duration of ≥40 ms (a sign of left atrial enlargement; the criterion is not specific to mitral valve disease)
- P pulmonale reflects enlargement or overload of the right atrium: a peaked P wave with an amplitude of ≥2.5 ms at a normal width, evaluated primarily in lead II, frequently also in III/aVF; in tricuspid and pulmonary valve diseases, it occurs mainly with pronounced right atrial overload or right ventricular failure, and does not in itself indicate a specific valvular defect
- Signs of left ventricular hypertrophy (aortic stenosis, mitral/aortic regurgitation): Sokolow–Lyon index S V1 + R V5 or V6 ≥35 ms, often with downsloping ST depression and a negative asymmetric T wave in I, aVL, V5–V6 (systolic overload); evaluate alongside other signs of LVH and clinical data, as a single voltage criterion does not diagnose LVH and has limited sensitivity
- Possible signs of right ventricular hypertrophy (mitral stenosis with pulmonary hypertension, tricuspid valve disease): R > S in V1, right axis deviation, deep S in V5–V6 — these are not sufficient criteria individually, but rather orientation points that require the exclusion of alternatives (infarction, right bundle branch block, posterior infarction, normal variant)
- Axis deviation: leftward in aortic valve disease and marked LVH; rightward in pulmonary hypertension and RV overload
- Conduction disorders: PR prolongation, left or right bundle branch block in calcification of the valvular apparatus and adjacent structures of the conduction system
- In atrial fibrillation: absence of discrete P waves, irregular RR intervals in the absence of complete AV block, assessment of ventricular response rate; f-waves may be detected in individual leads as an optional sign
What it looks like on ECG
The ECG in valvular heart disease is not specific to a particular defect, but reflects the hemodynamic overload of a specific chamber.
Left atrial enlargement is typical for mitral stenosis: P mitrale in lead II (broad, notched, ≥120 ms) and a terminal negative P wave phase in V1. With the development of pulmonary hypertension, signs of right ventricular hypertrophy join — right axis deviation, R > S in V1. AF often develops in severe or prolonged mitral stenosis, especially with left atrial dilatation, but may be absent: sinus rhythm with P mitrale is also possible over many years of the disease.
Left ventricular hypertrophy signs dominate in aortic stenosis: high Sokolow–Lyon index, and in severe disease, a pattern of "hypertrophy with systolic overload" (strain): downsloping ST depression and an asymmetric negative T wave in I, aVL, V5–V6. The electrical axis is often deviated to the left.
In chronic aortic regurgitation, volume overload can lead to marked dilatation and eccentric hypertrophy of the LV with high QRS voltages and prominent secondary ST-T changes, sometimes no less pronounced than in stenosis. In mitral regurgitation, left atrial and left ventricular enlargement dominate; the severity of LVH and strain depends on the severity and duration of regurgitation.
In tricuspid regurgitation, right atrial enlargement (P pulmonale) and signs of right ventricular overload/dilatation are more typical; marked RV hypertrophy and right bundle branch block are not mandatory and depend on the cause and severity of the defect. In tricuspid stenosis, changes may be predominantly restricted to the right atrium.
| Defect | Main finding |
|---|---|
| Mitral stenosis | P mitrale, possible AF, later signs of RV overload |
| Aortic stenosis | LVH with strain, left axis deviation |
| Aortic regurgitation | dilatation and eccentric LVH, high voltages |
| Mitral regurgitation | LA and LV enlargement, variable LVH |
| Tricuspid valve disease | RA enlargement, P pulmonale, RV overload/dilatation |
Mechanism
A valvular defect creates chronic pressure overload (stenosis) or volume overload (regurgitation) of the respective chamber. Pressure overload leads to concentric myocardial hypertrophy with increased QRS amplitude and secondary ST-T changes (strain pattern due to impaired repolarization of the hypertrophied wall). Volume overload usually causes chamber dilatation and eccentric hypertrophy; voltage changes in this case are variable and do not reliably allow assessment of defect severity, as ECG amplitude correlates poorly with anatomical mass and ventricular geometry. Atrial enlargement (stretching of its wall) slows and deforms the propagation of the depolarization wave, producing typical P mitrale and P pulmonale. Prolonged left atrial dilatation in mitral stenosis creates a substrate for the onset and maintenance of atrial fibrillation.
Causes
- Rheumatic mitral and/or aortic disease (historically the most common cause of P mitrale)
- Degenerative (calcific) aortic stenosis in the elderly
- Myxomatous mitral valve degeneration, mitral valve prolapse with mitral regurgitation
- Infective endocarditis with valvular regurgitation
- Secondary (functional) mitral or tricuspid regurgitation in ventricular dilatation
- Congenital heart disease with right-sided overload (e.g., atrial septal defect) — secondarily produces a pattern of RV overload
Differential diagnosis
- P mitrale in mitral valve disease and P mitrale due to other causes of left atrial enlargement (arterial hypertension, cardiomyopathy) — the ECG does not differentiate the cause, echocardiography is needed
- LVH with strain in aortic stenosis and ischemic ST-T changes — differentiated by the shape of the depression (downsloping, reciprocal to high R) and the clinical context
- P pulmonale in cor pulmonale (COPD) and P pulmonale in mitral stenosis with pulmonary hypertension — differentiated by echocardiography data and medical history
- AF in mitral valve disease and isolated AF without structural heart disease — requires echocardiography to rule out a valvular substrate
Clinical significance and management
ECG is an auxiliary method when valvular heart disease is suspected and a method for monitoring rhythm, conduction, and chamber overload signs; the key method for verification and assessment of defect severity is echocardiography. The detection of P mitrale, P pulmonale, or ventricular hypertrophy signs in a patient with a heart murmur warrants referral for echocardiography.
The detection of new-onset atrial fibrillation in a patient with mitral valve disease requires urgent clinical evaluation and a decision regarding anticoagulation, taking into account the type of valvular lesion: in mechanical heart valves, as well as in moderate or severe mitral stenosis regardless of etiology, a vitamin K antagonist is used; direct oral anticoagulants are not used in these situations. In other valvular heart diseases and AF, the choice of anticoagulant and assessment of thromboembolic risk are carried out according to current general criteria and contraindications for AF.
An increase in LVH voltage criteria and the appearance of a strain pattern in known aortic stenosis indicates progressive overload and requires more frequent monitoring. The ECG is also used for dynamic follow-up after valve replacement (new blocks, AV conduction disturbances during surgical or catheter intervention).
Common interpretation errors
- Diagnosing a specific valvular defect based on an ECG without echocardiography — the ECG only shows the consequence
- Missing P mitrale due to insufficient attention to the shape of the P wave in V1
- Mistaking the LVH strain pattern for ischemia and vice versa
- Failing to account for the fact that in severe AF, signs of atrial enlargement via the P wave cannot be evaluated
- Forgetting to look for signs of right-sided overload in primarily "left-sided" valvular diseases (secondary pulmonary hypertension)
1. Which ECG sign is most characteristic of mitral stenosis with left atrial enlargement?
Left atrial enlargement produces a characteristic delayed and deformed propagation of the atrial depolarization wave — P mitrale.
2. Which ECG pattern is typical for severe aortic stenosis with left ventricular hypertrophy?
Pressure overload in aortic stenosis causes concentric LV hypertrophy with a secondary repolarization strain pattern in the lateral leads.
3. What should the physician do upon detecting P mitrale and newly diagnosed atrial fibrillation on the ECG in a patient with a heart murmur?
The ECG findings indicate a probable valvular substrate, which requires echocardiographic verification and assessment of anticoagulation indications in AF, taking into account the type of valvular lesion.
Frequently asked questions
Can a heart valve defect be diagnosed via ECG?
No, the ECG shows only secondary signs — atrial enlargement, ventricular hypertrophy, arrhythmias. The diagnosis of a valvular defect and assessment of its severity are established by echocardiography, while ECG is used as an auxiliary method and to assess complications.
Why does atrial fibrillation frequently occur in mitral stenosis?
Chronic pressure elevation in the left atrium leads to its dilation and structural remodeling, creating an electrophysiological substrate for the initiation and maintenance of atrial fibrillation. However, with moderate or mild stenosis, the rhythm may remain sinus for a long time.
How does the ECG differ between aortic stenosis and aortic regurgitation?
In aortic stenosis, due to pressure overload, concentric LV hypertrophy with a strain pattern (downsloping ST depression, inverted T wave in lateral leads) is typical. In chronic aortic regurgitation, volume overload can produce equally pronounced voltages and eccentric LV hypertrophy, but the strain pattern is not always prominent and depends on the severity and duration of the defect.
Are ECG changes in heart valve defects dangerous?
The ECG changes themselves are not directly dangerous, but they reflect the progression of chamber overload and the risk of complications — atrial fibrillation with thromboembolism, heart failure, and conduction disorders due to mitral annular calcification.
What is P mitrale and is it always associated with mitral valve disease?
P mitrale is a broad, notched P wave in lead II and a terminal negative P wave phase in V1, reflecting left atrial enlargement. It is not specific to mitral valve disease and occurs with any cause of left atrial overload, including hypertension and cardiomyopathies.
ECG Course
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Related terms
More in the section "Pericardium, Lungs, Brain and Others"
Sources
- Orlov V.N. Guide to Electrocardiography
- Hampton J.R. The ECG in Practice
- Surawicz B., Knilans T.K. Chou's Electrocardiography in Clinical Practice
- Goldberger A.L. Clinical Electrocardiography: A Simplified Approach
Educational material for medical students and physicians. Does not replace clinical guidelines and physical examination; the ECG must always be interpreted in conjunction with the clinical picture.