From the Guidelines
Grade 1 diastolic dysfunction on echocardiography is characterized by an E/A ratio ≤ 0.8 along with a peak E velocity of ≤50 cm/sec, indicating normal or low left atrial pressure (LAP) and impaired relaxation of the left ventricle with preserved left ventricular ejection fraction. The determinants for characterizing Grade 1 diastolic dysfunction include:
- E/A ratio ≤ 0.8
- Peak E velocity ≤ 50 cm/sec
- Normal or low left atrial pressure (LAP)
- Impaired relaxation of the left ventricle with preserved left ventricular ejection fraction These findings are based on the recommendations for the evaluation of left ventricular diastolic function by echocardiography, as outlined in the European Heart Journal 1.
In patients with depressed EFs and in patients with normal EFs and myocardial disease, if the E/A ratio is ≤ 0.8 along with a peak E velocity of ≤50 cm/sec, then mean LAP is either normal or low and the patient has grade I diastolic dysfunction 1. Additionally, in patients with preserved EFs, the same initial evaluation of clinical presentation and 2D and color Doppler echocardiographic findings such as LVEF, regional wall motion abnormalities, LV hypertrophy, LA maximum volume index, and significant mitral valve disease is performed to aid the assessment of LV diastolic function 1.
The assessment of LV filling pressures is important in patients with HFrEF as it can successfully guide medical treatment 1. In patients with preserved EFs, cardiac structural as well as functional information should be used when assessing diastolic function, and an enlarged LA that is clearly larger than the right atrium in the optimally aligned apical four-chamber view is strongly suggestive of chronically elevated LV filling pressure, provided conditions such as anemia, atrial arrhythmias, and mitral valve disease can be excluded 1.
The E/A ratio and peak E velocity are the primary parameters used to determine the grade of diastolic dysfunction, with additional parameters such as peak TR velocity, E/e′ ratio, and LA maximum volume index used to estimate LAP when the E/A ratio and peak E velocity are not conclusive. If all three parameters are available for interpretation and only one of three meets the cutoff value, then LAP is normal and there is grade I diastolic dysfunction 1.
In summary, the characterization of Grade 1 diastolic dysfunction on echocardiography is based on the E/A ratio, peak E velocity, and left atrial pressure, with additional parameters used to estimate LAP when necessary, as recommended by the European Heart Journal 1.
From the Research
Determinants of Grade 1 Diastolic Dysfunction on Echo
The determinants for characterizing Grade 1 diastolic dysfunction on echo can be identified through various echocardiographic indicators.
- E/e' ratio: The average E/e' ratio over three cardiac cycles is a key indicator, with higher values suggesting diastolic dysfunction 2.
- Left atrial (LA) maximum volume index: An increased LA volume index is associated with diastolic dysfunction 2.
- Tricuspid regurgitation velocity: Elevated tricuspid regurgitation velocity is also a marker of diastolic dysfunction 2.
- LA strain: Reduced LA strain is indicative of diastolic dysfunction 2.
- Left ventricular isovolumic relaxation time (IVRT): Prolonged IVRT is a characteristic of diastolic dysfunction 2.
Association with ACE Gene Polymorphism
Research suggests that the angiotensin-converting enzyme (ACE) gene polymorphism, specifically the D allele, is associated with an increased risk of early diastolic dysfunction in hypertension 2.
- The D allele group showed a decline in diastolic function compared to the non-D allele group, with statistically significant differences in echocardiographic indicators 2.
- Logistic regression analysis revealed that the D allele is a significant predictor of early diastolic dysfunction in hypertension, with an odds ratio of 4.32 2.
Other Factors
While the provided studies do not directly address other determinants of Grade 1 diastolic dysfunction, they do discuss the effectiveness of various antihypertensive agents in treating hypertension and their potential impact on diastolic function 3, 4, 5, 6.