Alternation of left ventricular performance with electrical alternans

Area of Science:

• Cardiology
• Cardiac Electrophysiology
• Echocardiography

Background:

• Massive pericardial effusion can lead to electrical alternans, a beat-to-beat variation in the amplitude of electrocardiogram complexes.
• Systolic time intervals (STIs) provide insights into cardiac mechanical function and timing.
• Assessing STIs can help understand the impact of conditions like pericardial effusion on left ventricular performance.

Observation:

• Electrical alternans and variations in systolic time intervals were observed in a patient with massive pericardial effusion.
• Specific STI changes included shorter total electromechanical systole and left ventricular ejection time (LVET) following smaller QRS complexes.
• A prolonged pre-ejection time (PEP) and increased PEP/LVET ratio were noted in beats with smaller QRS complexes.

Findings:

• Beat-to-beat alterations in STIs correlated with electrical alternans, suggesting a corresponding alternation in left ventricular performance.
• The observed STI changes were directly linked to the presence of pericardial effusion and electrical alternans.
• Evacuation of pericardial fluid led to the disappearance of both electrical alternans and STI alternation.

Implications:

• STI analysis can be a valuable tool for detecting and quantifying cardiac performance alternations associated with electrical alternans in pericardial effusion.
• This case highlights the mechanical consequences of electrical alternans, demonstrating its impact on ventricular function.
• Monitoring STIs may aid in managing patients with pericardial effusion and associated electrical phenomena.