From the Guidelines
Late ventricular cycle, specifically late diastole, plays a crucial role in assessing left ventricular diastolic function, as it reflects the left atrium-left ventricle pressure gradient and is affected by left ventricular compliance and left atrial contractile function. This is evident from the mitral A velocity, which reflects the LA-LV pressure gradient during late diastole 1. The significance of late diastole can be understood by analyzing the utility, advantages, and limitations of variables used to assess LV diastolic function, such as mitral E velocity, mitral A velocity, mitral E/A ratio, and mitral E-velocity DT.
Some key points to consider when evaluating late diastole include:
- Mitral A velocity is feasible and reproducible, but its interpretation can be challenging in patients with sinus tachycardia, first-degree AV block, and paced rhythm, as it can result in fusion of the E and A waves 1.
- The mitral E/A ratio provides diagnostic and prognostic information, but its U-shaped relation with LV diastolic function makes it difficult to differentiate normal from pseudonormal filling, particularly with normal LVEF, without additional variables 1.
- Changes in mitral inflow with the Valsalva maneuver can help distinguish normal from pseudonormal filling patterns, but this maneuver may not be feasible in all patients and requires standardized conditions 1.
In clinical practice, assessing late diastole is essential for evaluating left ventricular diastolic function, and a comprehensive approach that considers multiple variables, such as mitral E velocity, mitral A velocity, mitral E/A ratio, and mitral E-velocity DT, is necessary for accurate diagnosis and prognosis. This approach can help identify patients with increased LV filling pressures and guide treatment decisions to improve morbidity, mortality, and quality of life outcomes 1.
From the Research
Significance of Late Ventricular Cycle (Late Diastole)
The late ventricular cycle, also known as late diastole, plays a crucial role in the cardiac cycle.
- It is the period when the ventricles are filling with blood, and the heart is preparing for the next contraction.
- During this phase, the ventricles relax, and the mitral and tricuspid valves open, allowing blood to flow into the ventricles 2.
- The late diastolic period is significant because it allows for the assessment of diastolic function, which is an indicator of the heart's ability to relax and fill with blood.
- Diastolic dysfunction has been linked to various cardiovascular diseases, including heart failure with preserved ejection fraction (HFpEF) 2.
Clinical Applications
The assessment of late diastolic function has several clinical applications, including:
- Evaluating the effectiveness of treatments for hypertension and heart failure 3.
- Identifying patients at risk of sudden cardiac death and ventricular arrhythmias 4.
- Monitoring the progression of cardiovascular diseases, such as hypertrophic cardiomyopathy 5, 6.
- Guiding the management of patients with cardiovascular diseases, including the use of implantable cardioverter-defibrillators (ICDs) and other treatments 5, 4.
Diagnostic Techniques
Various diagnostic techniques can be used to assess late diastolic function, including:
- Echocardiography, which can measure the E/A ratio and deceleration time of the early diastolic wave 3.
- Cardiac magnetic resonance imaging (MRI), which can evaluate diastolic function and detect subtle changes in cardiac function 2.
- Other imaging modalities, such as Doppler echocardiography, which can assess blood flow and ventricular function 6.