Pseudonormalization of transmitral pulsed doppler flow: A/e' ratio during the valsalva maneuver--a new discriminative index.

UNLABELLED: The Valsalva maneuver (VM) has frequently been suggested as a useful method in evaluation of left ventricular (LV) grade II diastolic dysfunction (DDII) through inversion of a pseudonormalized ratio between diastolic transmitral early (E) and late atrial (A) waves assessed by pulsed Doppler. The purpose of our study was to determine the sensitivity and specificity of E/A inversion during VM in LV DDII patients and its correlation with mitral annulus motion evaluated by tissue Doppler imaging (TDI). Using the echocardiographic criteria of the European Society of Cardiology for the diagnosis of diastolic dysfunction, we studied a group of 44 patients, 27 male, aged 59 +/- 14 years, with DDII (DDII-group) and compared them with a control group (N group) composed of 33 healthy individuals, 17 male, aged 36 +/- 9 years. Using transmitral pulsed Doppler analysis, we quantified the peak diastolic velocities of transmitral flow (E and A waves in cm/sec), pulmonary venous systodiastolic flow (PVF: S35 cm/sec) and the first aliasing LV diastolic flow propagation velocity by color M-mode Doppler (PVF <45 cm/sec for LV DDII). Using TDI we measured the peak systolic (s'), and diastolic rapid filling (e') and atrial (a') velocities (Vm in cm/sec) at four points of the mitral annulus: adjacent to the interventricular septum (P4), and the lateral (P2), inferior (P3) and anterior (P4) LV walls. VM was performed by all patients, with repeated measurements of the above parameters (except for PVF) at the point of their maximum shift. RESULTS: Four patients in the DDII-group were excluded due to degradation of the acoustic window during VM. The sensitivity and specificity of E/A inversion during VM in diagnosing LV DDII were respectively 88% and 57%. On ROC curve analysis, the most discriminative index for DDII diagnosis A/e' > 4.06 in P2 during VM (area under ROC curve [AUROC] = 0.883 [0, 78, 0, 94]). There was a significant increase in AUROC (0.74 vs. 0.88, p = 0.006) during VM. For A/e' > 4.06, the sensitivity and specificity for DDII diagnosis were respectively 62% and 78% pre-VM and 85% and 78% during VM. CONCLUSIONS: Inversion of a pseudonormalized pulsed Doppler E/A ratio during VM has high sensitivity, but its low specificity makes it of little clinical use. An A/e' ratio > 4.1 during VM is a new, highly discriminative index that can be used in practice to diagnose LV grade II diastolic dysfunction in the presence of a pseudonormalized pulsed Doppler E/A ratio.

Assessment of T-wave alternans after acute myocardial infarction: influence of the timing of PTCA on cardiac electrical stabilization.

UNLABELLED: It is accepted that the timing of myocardial revascularization in patients undergoing PTCA for the treatment of acute myocardial infarction (AMI) may improve the clinical outcome. However, its impact on microvolt T-wave alternans (TWA), a recognized tool for assessing vulnerability to ventricular tachyarrhythmias that can cause sudden cardiac death in infarction survivors, remains unknown. AIM: To analyze TWA in patients with AMI treated by PTCA and assess whether the timing of myocardial revascularization can influence TWA measurements. METHODS: We studied 79 patients (67 male; 57 +/- 11 years) who underwent successful PTCA for the treatment of AMI. The presence of TWA was assessed using a HearTwave system (Cambridge Heart, Inc.) within 30 days of AMI. Orthogonal Frank XYZ leads and associated vector magnitude (microvolt alternans sensors) and 7 standard ECG leads were recorded during a treadmill manual exercise protocol to increase heart rate slowly to approximately 110 bpm. TWA was considered positive if the sustained alternans microvoltage was > or = 1.9 microV at heart rates of > 100 bpm, negative if the criteria for positivity were not met while maintaining heart rate at > or =105 bpm (maximum negative heart rate), and inconclusive if it could not be definitively classified as either positive or negative. Patients were excluded if they had atrial fibrillation, > 10 extrasystoles/min, bradycardia 40 beats/min, wide QRS complex, congestive heart failure or implanted pacemaker, or were under antiarrhythmic therapy. The presence of positive or inconclusive TWA (non-negative TWA) was considered a risk marker for the occurrence of life-threatening ventricular arrhythmias. TWA results were compared between the group of patients who underwent PTCA within 24h of AMI (early PTCA; n=45) and those treated >24h after hospital admission (late PTCA; n=34). RESULTS: TWA was positive in 16 patients (20.2%), negative in 56 (70.9%) and inconclusive in 7 (8.9%). Overall, TWA was non-negative in 29.1% of the patients. In the early PTCA group, TWA was non-negative in 9 patients (20%) (6 positive and 3 inconclusive) and negative in 36 (80%). In the late PTCA group, TWA was non-negative in 14 patients (41%) (10 positive and 4 inconclusive) and negative in 20 (59%) (p < 0.05). There were no differences in left ventricular ejection fraction between the two groups. No spontaneous ventricular arrhythmias, syncope or deaths were recorded in the first 60 days after hospital discharge. Five patients (7%) were re-admitted with angina. CONCLUSIONS: In a population of AMI survivors: a) the prevalence of non-negative TWA was 25%, despite myocardial revascularization by PTCA; b) PTCA performed within 24h of onset of AMI significantly reduced the number of patients with non-negative TWA, suggesting a lower arrhythmic risk. These findings should be investigated in larger studies.

Contrast echocardiography in segmental analysis and intraventricular gradient quantification in hypertrophic cardiomyopathy.

INTRODUCTION: Hypertrophic cardiomyopathy (HCM) is a hereditary disorder characterized by ventricular hypertrophy, diastolic dysfunction and hyperdynamic left ventricular systolic function. This excessive contraction is sometimes associated with significant intraventricular pressure gradients. These gradients are dynamic and therefore vary at different times. Echocardiography can identify and quantify the functional and morphologic changes characteristic of the disease. Ultrasound contrast agents (UCAs) are indicated in patients with poor transthoracic image quality, enabling better visualization of the endocardial border. These agents also strengthen the Doppler signal, which enables better quantification of the transvalvular and intraventricular gradients. In HCM, definition of the endocardial/blood interface and visualization of the myocardial structure, as well as quantification of intraventricular gradients, are fundamental to the study of the pathology. OBJECTIVES: The objective of this study was to evaluate the clinical utility of new UCAs in morphologic study (segmental analysis) and quantification of maximum intraventricular gradients (IVG Max) in HCM, as well as the feasibility and interest of determining mean gradients (IVG Med) in HCM. METHODS: Thirty-four patients with clinical and echocardiographic diagnosis of HCM were studied. Baseline IVG was considered significant when over 30 mmHg. Left ventricular morphology and IVG quantification were assessed before (study A) and after (study B) UCA injection. Maximum (Max) and mean (Med) values of delta IVG were calculated. Endocardial border definition of ventricular segments was analyzed in studies A and B and the percentage of ventricular segments that were completely visualized throughout the cardiac cycle was established. RESULTS: The mean values of delta IVG Max for studies A and B were 51 +/- 31 mmHg and 61 +/- 32 mmHg, p = NS. The mean values of delta IVG Med were 26 +/- 16 mmHg in study A and 31 +/- 17 mmHg in study B, p = NS. The correlation between delta IVG Max and Med in study A was r2 = 0.74, p < 0.01, while in study B it rose to a value of r2 = 0.82, p < 0.01. Segmental analysis: In all segments studied the visualization percentage was higher after UCA injection, with a statistically significant difference in all lateral and anterior wall segments. DISCUSSION AND CONCLUSIONS: HCM is usually evaluated in a non-invasive way by echocardiography. There are no references to systematic use of UCAs in HCM patients. The value of determining the maximum gradient in HCM is generally accepted, but the importance of the mean gradient is not known. In this work, UCAs improved the Doppler signal without distorting values. In HCM, values measured using UCAs have a better correlation, with a smaller discrepancy between Max and Med gradients. This study suggests that mean gradient determination enables better characterization of the dynamic variability of the gradients because there is a correlation between Max and Med gradients. The real importance of mean gradients is not yet established, so further studies are necessary. In conclusion. UCAs are very useful in morphological assessment. The interest of UCAs in determining intraventricular gradients and the value of mean gradients in HCM are not clearly demonstrated in this study.