What is the management approach for patients presenting with left vs. right ventricular strain patterns?

Management of Left vs. Right Ventricular Strain Patterns

The management approach differs fundamentally based on whether strain abnormalities originate from the left or right ventricle, with treatment directed at the underlying pathophysiology: for LV strain abnormalities, focus on coronary disease, hypertension, and cardiomyopathy management; for RV strain abnormalities, prioritize pulmonary hypertension treatment, volume optimization, and addressing right-sided valvular disease. 1

Initial Diagnostic Approach

Distinguishing LV vs. RV Strain Patterns

Left Ventricular Strain Pattern Recognition:

• LV global longitudinal strain (GLS) worse than -18% indicates abnormal LV function and warrants investigation for ischemia, hypertrophy, or infiltrative disease 1, 2
• Regional strain abnormalities in LV basal segments suggest coronary artery disease, particularly when accompanied by ST-segment changes 1
• LV circumferential strain reduction (worse than -20%) indicates more advanced myocardial dysfunction 3, 2

Right Ventricular Strain Pattern Recognition:

• RV global longitudinal strain worse than -17.9% or RV free wall strain worse than -21.2% indicates RV dysfunction requiring evaluation for pulmonary hypertension, pulmonary embolism, or arrhythmogenic cardiomyopathy 1, 4
• RV basal free wall hypokinesia with preserved apical function (McConnell sign) suggests acute pulmonary embolism, though this is not entirely specific 1
• RV/LV diameter ratio >0.6 or area ratio >1.0 at end-diastole indicates significant RV pressure overload 1

Management Based on Ventricular Involvement

Left Ventricular Strain Abnormalities

Acute Presentations:

• When LV strain abnormalities present with chest pain and ST-segment depression ≥2 mm, consider posterior myocardial infarction and evaluate for reperfusion therapy 1
• Obtain cardiac biomarkers (troponin T or I) immediately to assess for acute coronary syndrome 1
• Perform urgent coronary angiography if troponin-positive with ongoing symptoms or hemodynamic instability 1

Chronic LV Dysfunction Management:

• Initiate renin-angiotensin system antagonists and mineralocorticoid receptor antagonists, which independently predict improved prognosis in patients with LV diastolic dysfunction 1
• Beta-blockers are recommended for patients with coronary artery disease and reduced LV strain 5
• Monitor for progression: LV hypertrophy, increased LA size, and elevated E/e' ratio independently predict worse outcomes and should trigger treatment intensification 1

Prognostic Monitoring:

• Serial LV GLS measurements provide incremental prognostic information beyond ejection fraction for predicting heart failure hospitalization and mortality 1, 2
• Grade II or III diastolic dysfunction that fails to improve despite optimal medical therapy predicts worse outcomes and may warrant advanced heart failure therapies 1

Right Ventricular Strain Abnormalities

Acute RV Strain (Suspected Pulmonary Embolism):

• The absence of RV pressure overload or dysfunction on echocardiography virtually excludes massive pulmonary embolism as the cause of hemodynamic instability 1
• When RV dysfunction is present with suspected PE, stratify risk: intermediate-risk patients (RV dysfunction without shock) versus high-risk patients (shock/hypotension requiring different management intensity) 1
• Measure tricuspid regurgitation velocity to estimate pulmonary artery systolic pressure; this helps differentiate acute from chronic RV pressure overload 1

Chronic RV Dysfunction Management:

• Diuretics are the primary therapy for patients with severe RV dysfunction and signs of right-sided heart failure (peripheral edema, ascites) 1
• Loop diuretics relieve systemic congestion but may worsen low-flow syndrome; aldosterone antagonists provide additive benefit, especially with hepatic congestion 1
• Medical therapies to reduce pulmonary artery pressures (pulmonary vasodilators) should be considered in patients demonstrating acute responsiveness during invasive testing 1

Surgical Considerations for RV Dysfunction:

• Tricuspid valve surgery is recommended for patients with severe TR undergoing left-sided valve surgery, as severe TR does not predictably improve after left-sided valve repair alone 1
• Assess RV systolic function with CMR or 3D echocardiography when 2D imaging is suboptimal, as impaired RV function negatively impacts surgical outcomes 1

Ventricular Interdependence Considerations

Septal Involvement:

• In pulmonary hypertension, the interventricular septum shows the most pronounced LV strain abnormalities due to septal shift and shared ventricular mechanics 6
• Basal septal LV longitudinal strain correlates strongly with degree of pulmonary hypertension (r=0.66), pulmonary vascular resistance (r=0.60), and RV free-wall strain (r=0.64) 6
• Combined average strain of basal and mid interventricular septal segments provides the best correlation with invasive hemodynamics 6

Biventricular Dysfunction:

• When both ventricles show strain abnormalities, prioritize treating the primary pathology: optimize left-sided filling pressures and systemic hypertension to reduce RV afterload 1
• Brain natriuretic peptide levels correlate moderately with septal strain (r=0.48) and can guide treatment intensity 6

Arrhythmia Management in Strain Patterns

Ventricular Tachycardia with Strain Abnormalities

Right Bundle Branch Block (RBBB) Morphology VT:

• RBBB morphology with left axis deviation suggests left posterior fascicular VT; administer IV verapamil as first-line acute treatment in hemodynamically stable patients 1, 7
• Catheter ablation is recommended as first-line definitive treatment for symptomatic fascicular VT, with success rates exceeding 90% 1, 7
• Beta-blockers are an alternative if verapamil is contraindicated 7

Left Bundle Branch Block (LBBB) Morphology:

• New or presumably new LBBB with symptoms suggesting acute myocardial infarction warrants consideration for reperfusion therapy, though only ~10% of chest pain patients with LBBB actually have AMI 1
• Both RBBB and LBBB can obscure ST-segment analysis; patients with either pattern have increased mortality (RBBB: 64% increased odds ratio; LBBB: 34% increased odds ratio) compared to patients without bundle branch block 1

Specific Disease States

Arrhythmogenic Cardiomyopathy (AC)

Diagnostic Criteria:

• RV fractional area change <40%, TAPSE <17 mm, or RV longitudinal strain of lateral free wall worse than -23% meets imaging criteria for AC 1
• RV mechanical dispersion (SD of time-to-peak strain) >25-30 ms suggests AC 1
• Abnormal RV strain identifies 59-81% of patients who meet overall AC diagnostic criteria but are missed by conventional echocardiographic criteria 4

Prognostic Assessment:

• LV global longitudinal strain does not add diagnostic value for AC but is prognostic for composite endpoints of death, heart transplantation, or ventricular arrhythmia 4
• Follow-up intervals depend on physiological stage: Stage A every 24-36 months, Stage B every 24 months, Stage C every 6-12 months, Stage D every 3-6 months 1

Congenital Heart Disease

Post-Atrial Switch (D-TGA):

• Systemic RV shows decreased global longitudinal strain (-12.9% vs. -18.9% in controls) but maintains normal circumferential strain 3
• Subpulmonary LV demonstrates higher circumferential strain than subpulmonary RV, reflecting adaptation to altered loading conditions 3

Critical Pitfalls to Avoid

• Do not use class IC antiarrhythmic drugs in patients with history of myocardial infarction or structural heart disease, as they are contraindicated 1, 7, 5
• Do not rely solely on LVEF for assessing ventricular function when strain imaging is available, as subclinical dysfunction is missed by ejection fraction alone 2, 8
• Do not assume RV dysfunction will improve after left-sided valve surgery; address severe tricuspid regurgitation during the index procedure 1
• Do not treat isolated NSVT with antiarrhythmic drugs in asymptomatic patients without structural heart disease 5
• Do not use IV amiodarone as first-line therapy for fascicular VT when verapamil or beta-blockers are available 7