Systolic Time Research Articles

Serum uric acid and coronary heart disease in patients with essential hypertension

with coronary heart disease (CHD) with multiple tissue Doppler imaging(TDI) parameters in rest state and to discuss the value of regional cardiac function in diagnosing CHD. Design and methods: Forty-seven inpatients with chief complaint of chest pain underwent TDI examination. Maximum systolic velocity (Sm), maximum early diastolic velocity (Em), maximum late diastolic velocity (Am), isovoluminal contraction time (IVCT) and isovoluminal relaxation time (IVRT) of sixteen segments of left ventricle were measured. All the patients underwent coronary angiography (CAG) at the same time. CHD was diagnosed by at least one coronary artery with no less than 50% diametric stenosis. Segments dominated by coronary artery with 50 to 90 and more than 90% diametric stenosis were moderate and severe lesion segments respectively. Others were non-lesion segments. Results: No obvious influences were observed in left ventricular ejection fraction (LVEF) and E/A ratio in different coronary lesions. Compared with non-lesion segments, velocity parameters Sm, Em and Em/Am of lesion segments decreased, and time parameters IVCT and IVRT prolonged. If setting a criterion that no less than three segments with Sm − 2.50 cm/s and IVRT>87 ms for CHD diagnosis, the sensitivity, specificity, positive predictive value and negative predictive value were 79.4%, 84.6%, 93.1% and 61.1%. Conclusions: In rest state, regional cardiac function of lesion segments in CHD patients showed changes of decreased systolic and diastolic velocities and prolonged isovoluminal time. Analysing segmental cardiac velocity and time comprehensively may help diagnose CHD.

A preliminary study on the evaluation of relationship between left ventricular torsion and cardiac cycle phase by two-dimensional ultrasound speckle tracking imaging

In normal subjects there is a certain corresponding relationship between the peak rotation angle of the apex and the base with respect to the phase of the cardiac cycle. We hypothesized that the myocardial contractile force and the delay of conduction may affect the correspondence of them. Our study aims to use speckle tracking imaging (STI) technique to analyze the relationship between the left ventricular rotation/torsion (LVrot/ LVtor ) characteristics and cardiac cycle phase, to investigate its clinical feasibility. The echocardiographic images of the short-axis view of the left ventricles (LV) at the apical and basal planes were acquired by STI in 32 healthy controls and 48 heart failure patients (New York Heart Association class I or II). LVtor angle, LVrot angle, the peak value and time of LVtor and LVrot were measured offline using frame-to-frame tracking of gray-scale speckle patterns at the standardized time point, respectively. All the acquired data of the two groups were compared and analyzed. In the healthy controls, there was no significant difference among the isovolumetric contraction time, peak time of clockwise rotation at the apical level and the peak time of clockwise rotation at the basal level segments (P > 0.05). There was no significant difference among systolic time, peak time of counterclockwise rotation at the apical level and peak time of counterclockwise rotation at the basal level segments (P > 0.05). There was no significant difference between systolic time and peak time of LVtor (P > 0.05). Compared with normal group, the peak of LVtor and LVrot angle were decreased at both apical and basal planes in heart failure group (P < 0.05). The peak time of LVtor was delayed in heart failure group (P < 0.05). The peak time of clockwise rotation at the apical level segments was longer than control group (P < 0.05) and continued to the ejection period. In the normal subjects, there is no sequence difference of LVrot between the basal and apical planes. They were correspondent to cardiac cycle. There is a temporal sequence difference of LVrot between basal and apical planes during LV contraction in heart failure group and decreased LVtor/rot have been demonstrated to influence left ventricular function. STI has shown great potential in early detecting the conduction variability in ventricular wall.

SUBENDOCARDIAL VIABILITY INDEX IS RELATED TO THE DIASTOLIC/SYSTOLIC TIME RATIO AND LEFT VENTRICULAR FILLING PRESSURE, NOT TO AORTIC PRESSURE: AN INVASIVE STUDY IN RESTING HUMANS

1. The myocardial perfusion relative to left ventricular (LV) workload may be estimated by the subendocardial viability index (SVI). The SVI is a pressure-time integral ratio: the numerator is the area between aortic and LV pressures during diastolic time (DT) and the denominator is the area under the LV pressure curve during systolic time (ST). New non-invasive tonometric devices allow estimation of SVI but neglect LV end-diastolic pressure (LVEDP) in the calculation. The aim of the present study was to determine the haemodynamic correlates of SVI and to test the effects of neglecting LVEDP on SVI estimation. 2. High-fidelity pressures were recorded at rest at the aortic root and LV level in 38 subjects (33 men/five women; mean (+/-SD) age 47 +/- 14 years; nine controls and 29 patients with various cardiac diseases). The SVI (1.16 +/- 0.28) was positively correlated with the DT/ST ratio (1.71 +/- 0.35; r(2) = 0.81) and was negatively correlated with LVEDP (15 +/- 7 mmHg; multiple r(2) = 0.94). The SVI was not related to aortic pressure (mean, pulse, mean systolic, mean diastolic). In 17 patients with LVEDP > 14 mmHg, the SVI calculated assuming zero LVEDP was 33 +/- 15% higher (range 16-70%) than the actual SVI. 3. The DT/ST ratio was the main determinant of the myocardial perfusion relative to cardiac workload and accounted for 81% of SVI variability, whereas aortic pressure did not contribute. Although LVEDP accounted for only 13% of SVI variability, it should be taken into account in the non-invasive calculation of SVI in patients with known or suspected increases in LV filling pressure.

Abstract 325: Administration Of Apelin Modulates Myocardial Expression Of Apelin-apj And Improves Right Ventricular Performance In Mct-induced Pulmonary Hypertension

Background: Apelin (AP) is the endogenous vasoactive ligand of APJ receptor. It is widely expressed in the heart and lungs and has important cardiovascular functions such as endothelium-dependent vasodilatation and positive inotropic effect. However, the role of apelin-APJ system in pulmonary hypertension (PH) remains to be clarified. Objective: To evaluate the chronic effects of apelin in: right ventricular (RV) myocardial function; cardiac expression of apelin and APJ in healthy and MCT-PH rats Methods: Male Wistar rats were randomly injected with MCT (60mg/Kg, sc) or vehicle (CTR, day 0). One week later, half of these animals were randomly treated with Pyr-apelin-13 (200μg/Kg/day, ip) or a similar volume of vehicle. The study resulted in 4 groups: CTR; AP; MCT and MCT+ AP. At day 24, animals were instrumented to record RV peak systolic (Pmax) pressures, dP/dtmax, dP/dtmin and time constant Tau. Also, heart and lungs were weighted and transmural RV samples were collected for relative quantification of mRNA by real-time RT-PCR. Results are on table . Conclusions: In healthy rats, exogenous apelin potentiates its endogenous production with no significant changes in APJ. MCT-induced PH resulted in a significant down-regulation of apelin-APJ system, which might play a role in the systolic and diastolic dysfunction observed in this model. This down-regulation was completely reverted by chronic administration of exogenous apelin. Therefore, apelin upregulates the cardiac apelin-APJ system exerting beneficial effects on cardiac remodeling and function, namely, by decreasing PH, RV diastolic function and hypertrophy. These results reveal the importance of apelin-APJ system in the pathophysiology of PH, suggesting that apelin is a potential therapeutic target in this disease. Results table

Abstract 4473: Coronary Flow Velocity Pattern Immediately after Percutaneous Coronary Intervention Predicts True Left Ventricular Aneurysm in Patients with Acute Anterior Myocardial Infarction

Aggressive management of acute myocardial infarction (AMI), including prompt reperfusion, may diminish the incidence of true left ventricular (LV) aneurysm; however, it has been reported that even if successful reperfusion is achieved in epicardial coronary arteries, microvascular dysfunction causes insufficient reperfusion of the infracted myocardium, leading to LV dysfunction. Recent studies have shown that microvascular damage can be assessed quantitatively from coronary flow velocity (CFV) patterns immediately after successful reperfusion. The purpose of this study was to examine whether the CFV patterns may predict the risk of true LV aneurysm formation following successful percutaneous coronary intervention (PCI). Two hundred and one consecutive patients with first anterior AMI who underwent successful PCI were subjected to CFV measurement immediately after PCI with Doppler guidewires. The CFV spectrum provided systolic peak velocity (cm/s, SPV) and diastolic deceleration time (ms, DDT). Left ventriculogram obtained 6 months after the infarction was analyzed to measure the LV volume index. True LV aneurysm was defined as a deformity of the infarct segment that was apparent during diastole as well as during systole, and demonstrated diastolic contour abnormality. Patients were divided into the two groups: those subsequently complicated by true LV aneurysm (n=42; group 1) and those without true LV aneurysm (n=159; group 2) CFV analysis immediately after PCI showed significantly lower SPV (−29 ± 17 vs. 5 ± 22 cm/s; p&lt;0.001) and shorter DDT (317 ± 156 vs. 665 ± 204 ms; p&lt;0.001) in group 1 than in group 2. The optimal cutoff values to predict true LV aneurysm formation were −20 cm/s for SPV and 400 ms for DDT (sensitivity=0.83, specificity=0.82; and sensitivity=0.81, specificity=0.87, respectively). SPV and DDT correlated to the LV end-diastolic volume index obtained 6 months after AMI (r= −0.67; p&lt;0.001 and r = −0.78; p&lt;0.001, respectively). CFV pattern of infarct-related coronary artery immediately after PCI predicts true LV aneurysm formation, and enables accurate risk stratification in patients with anterior AMI.

Abstract 2007: Effects of Myocardial Viability Assessed by Strain Stress Echocardiography on Diastolic Function in Acute Myocardial Infarction

Purpose: Myocardial viability may influence the diastolic function of left ventricle (LV) reflecting chamber remodeling in the early phase after acute myocardial infarction (AMI). However, the precise relationship in human has not been determined yet. So we aimed to evaluate whether myocardial viability assessed by strain rate parameters on low-dose dobutamine echocardiography (LD-DSE) may influence on LV diastolic function and remodeling process in AMI. Methods: In this prospective single center study, 134 consecutive patients with AMI and akinetic wall motion in at least two segments were enrolled and underwent LD-DSE on 5~9 days after the event. Myocardial viability was quantitatively evaluated by global peak systolic strain rate (psSR) and global time to peak of psSR. Within 6 hours after LD-DSE, left and right heart catheterization with the recording of LV end diastolic pressure and pulmonary capillary wedge pressure were performed. And then 6 months later, echocardiography and thallium scan with delayed image were followed. Results: Patients (67.9% men, mean age 60.1±1.1years, 54.5% anterior wall, 53.7% ST-segment elevation) were tolerated LD-DSE without significant complications. 71.6% of patients underwent revascularization therapy. After 6 months later, LV ejection fraction was significantly increased from 48.7±1.1% to 52.0±1.1% (p=0.00) and LV end diastolic volume was significantly decreased from 94.6±4.0cc to 89.1±3.8cc (p=0.00). As we expected, global psSR at baseline of LD-DSE showed significant linear correlations with LV end diastolic pressure, E/E’ ratio and left atrial volume index (r=−0.43 and p=0.01, r=0.52 and p=0.00 and r=0.52 and p=0.00, respectively). And also global psSR at 10mcg of LD-DSE correlated with E/E’ ratio and left atrial volume index(r=0.52 and p=0.00 and r=0.36 and p=0.02, respectively). Interestingly, global psSR at 10mcg of LD-DSE correlated significantly with the change of LV end diastolic volume during 6 months follow-up (r=−0.42 and p=0.04). Conclusions: Strain rate data on LD-DSE correlates with LV diastolic function in the early phase and chamber remodeling in 6 months follow-up after AMI. So strain stress echocardiography may provide useful prognostic information for LV remodeling in AMI.

SUBENDOCARDIAL VIABILITY RATIO ESTIMATED BY ARTERIAL TONOMETRY: A CRITICAL EVALUATION IN ELDERLY HYPERTENSIVE PATIENTS WITH INCREASED AORTIC STIFFNESS

1. Increased aortic stiffness predisposes to myocardial ischaemia by increasing the systolic tension-time index and by decreasing aortic pressure throughout diastole. The tonometric subendocardial viability ratio (SEVR) is a non-invasive estimate of myocardial perfusion relative to cardiac workload. The hypothesis that SEVR is impaired in elderly hypertensives with high aortic pulse pressure (PP) was tested in the present study. 2. The SEVR was calculated by radial applanation tonometry in 203 subjects. In addition, diastolic time (DT), systolic time (ST) and mean diastolic and systolic aortic pressures (Pd and Ps, respectively) were calculated. First, 60 subjects matched for age and gender were analysed (20 controls, 20 hypertensives with pulse pressure (PP) < or = 60 mmHg, 20 hypertensives with PP > 60 mmHg; mean (+/-SD) age 64 +/- 9 years; 24 women, 36 men). The remaining 143 subjects, aged 53 +/- 10 years, were analysed subsequently. 3. The SEVR was similar in the three elderly groups (1.39 +/- 0.34, 1.39 +/- 0.28 and 1.35 +/- 0.25, in controls and hypertensive patients with PP < or = 60 and > 60 mmHg, respectively). The SEVR was positively related to DT/ST (r(2) = 0.89) and to DT (r(2) = 0.73) and was negatively related to heart rate (r(2) = 0.56; P < 0.001 each). However, SEVR was not related to ST, PP, mean Pd or mean Ps. At a given DT/ST, SEVR tended to be lower in hypertensives with PP > 60 mmHg than in hypertensives with normal PP. The positive linear relationship between SEVR and DT/ST was confirmed in the remaining 143 subjects (r(2) = 0.90), with no influence of aortic pressure. 4. The tonometric SEVR was not impaired in elderly hypertensive patients with increased aortic stiffness. In resting elderly and middle-aged individuals, the tonometric SEVR was mainly related to DT/ST ratio, not to aortic pressure.

NUMERICAL AND EXPERIMENTAL FLUID-STRUCTURE INTERACTION MODELS OF A PROSTHETIC AORTIC VALVE

Geometrical models are the same in both numerical and experimental simulations. They consist of a rigid straight tube at the entrance (resp. at the outflow) simulating the left ventricle outflow tract (resp. the aorta). The bileaflet valve is a 27 mm St Jude valve. The sinuses of Valsalva are supposed axisymmetrical. At the entrance, a long enough tube ensures a fully developed flow. The inlet conditions are then velocity profiles defined from the Womersley solution [Womersley, 1955]. The shape of the flow rate is physiological. The outlet conditions are considered as free conditions. The fluid is assumed to be Newtonian and viscous as the blood ( =4.0 cP, =1130 kg/m). The flow is 3D, laminar and unsteady. These boundary and hydrodynamic conditions are the same in both numerical and experimental simulations. The numerical simulation is realized with the commercial software Fluent (Fluent Inc, Lebanon, USA). FSI is taken into account through pressure and viscous forces on each leaflet. The resultant moment is then calculated. A sub iteration loop [Dumont, 2004] is managed in each time step to ensure a strong coupling between the fluid and the structure. The experimental simulation is conducted in a rigid Plexiglas model inserted in a circulatory mock loop model. Pressure and flow rate measurements are recorded. The fluid is seeded with nylon particles. PIV measurements are realized in two perpendicular plans, during the systolic ejection time.

Effects Of Compression Timing On Femoral Blood Flow During Rhythmical Calf Compression Synchronized To HR

Arterial blood flow is not a steady stream; it is pulsatile, which means that during the cardiac cycle the blood flow rate in the arteries varies depending on the timing of the flow wave. Given that rhythmical muscle contraction can temporarily obstruct blood flow by externally compressing the veins and arteries, we hypothesized that with rhythmical muscle contraction, the timing of the vessel compressions during the cardiac cycle will affect the muscle blood flow response. Furthermore, the blood flow response can depend on the level of the pressure and the body posture. PURPOSE: To investigate the effects of timing, the level of the pressure and posture on femoral arterial blood flow (FBF) during rhythmical external calf compressions synchronized to the heartbeat. METHODS: In 10 male subjects, a calf cuff was rhythmically inflated for 250 ms. In experiment 1 (EX1), the inflation was triggered 140-ms after the ECG-R wave (systolic timing: ST), 40 ms after the R wave (diastolic timing: DT), or at a constant rate irrespective of the resting HR (Random timing: RT). In experiment 2 (EX2), external compressions at three pressures (70, 130, 190 mmHg) were applied with DT. Each compression was applied for 3 min while the subject was in a supine position (SUP) or a 60° head-up tilt (HUT). FBF determined using the Doppler ultrasound method and cardiovascular responses were measured. RESULTS: In EX1, FBF was markedly increased after compression for 1 min, then gradually declined, but remained higher than resting level with all compressions. In a SUP, the increase in FBF with ST was smaller than with DT or RT. In a HUT, the increase in FBF was greater than in a SUP and differed among the three timing protocols. In EX2, in a SUP, the increase in FBF with 190 mmHg compressions was greater than with 70 or 130 mmHg compressions. With 130 or 190 mmHg compressions, the increase in FBF was smaller when the subject was in a HUT than when he was in a SUP. CONCLUSION: These results suggest that during rhythmical calf compression synchronized to the cardiac cycle, the contraction timing, the pressure level and posture all influence FBF. (1798/2000 characters). Supported by grants from COE projects, and from the Ministry of Education, Science, and Culture, Japan.

Diastolic time – frequency relation in the stress echo lab: filling timing and flow at different heart rates

A cutaneous force-frequency relation recording system based on first heart sound amplitude vibrations has been recently validated. Second heart sound can be simultaneously recorded in order to quantify both systole and diastole duration.Aims1- To assess the feasibility and extra-value of operator-independent, force sensor-based, diastolic time recording during stress.MethodsWe enrolled 161 patients referred for stress echocardiography (exercise 115, dipyridamole 40, pacing 6 patients).The sensor was fastened in the precordial region by a standard ECG electrode. The acceleration signal was converted into digital and recorded together with ECG signal.Both systolic and diastolic times were acquired continuously during stress and were displayed by plotting times vs. heart rate. Diastolic filling rate was calculated as echo-measured mitral filling volume/sensor-monitored diastolic time.ResultsDiastolic time decreased during stress more markedly than systolic time. At peak stress 62 of the 161 pts showed reversal of the systolic/diastolic ratio with the duration of systole longer than diastole. In the exercise group, at 100 bpm HR, systolic/diastolic time ratio was lower in the 17 controls (0.74 ± 0.12) than in patients (0.86 ± 0.10, p < 0.05 vs. controls).Diastolic filling rate increased from 101 ± 36 (rest) to 219 ± 92 ml/m2* s-1 at peak stress (p < 0.5 vs. rest).ConclusionCardiological systolic and diastolic duration can be monitored during stress by using an acceleration force sensor. Simultaneous calculation of stroke volume allows monitoring diastolic filling rate.Stress-induced "systolic-diastolic mismatch" can be easily quantified and is associated to several cardiac diseases, possibly expanding the spectrum of information obtainable during stress.

Slow contractions characterize failing rat hearts

The reduced power of the failing heart can be ascribed to a combination of reduced force and slower contraction. We hypothesized that these two properties are due to different cellular mechanisms. We measured contraction parameters both in vivo and in isolated left ventricular (LV) cardiomyocytes from a rat model of post infarction congestive heart failure (CHF). ECG was measured simultaneously with echocardiography and LV pressure, respectively. Shortening and shortening velocity (SV) in isolated cardiomyocytes were measured during different stimulation protocols. LV end diastolic pressure (LVEDP) was 24.6 +/- 0.7 mmHg in CHF. LV systolic pressure was decreased by 20%, maximum rate of pressure development in the LV (+dP/dtmax) by 36% and time in systole increased by 20% in CHF compared to sham. Electrical remodelling occurred in CHF cells, which were depolarized and had prolonged action potentials (AP) compared to sham cells. Fractional shortening (FS) was increased in CHF compared to sham independent of stimulation protocol. Larger FS was accompanied by increased sarcoplasmic reticulum (SR) Ca2+ load and depended on the electrical remodelling. Time to peak contraction (TTP) was increased in CHF compared to sham cells, but in contrast to FS, TTP was only slightly affected when the cells were stimulated with sham APs and sham diastolic membrane potential (DMP). Contraction duration (corresponding to systolic duration) was 25% longer in CHF than in sham independent on stimulation protocol. We conclude that electrical remodelling affecting DMP and AP duration (APD) significantly affects the size of contraction, whereas the mechanism for slowing of contraction in CHF is different.

Dynamics of cardiac output in patients with hypertrophic obstructive cardiomyopathy

To characterise the duration of aortic flow velocity waveforms in hypertrophic obstructive cardiomyopathy (HOCM) the dynamics of aortic flow were investigated in 10 normals and 11 patients with hypertrophic obstructive cardiomyopathy performing 16-gated Doppler 2D-echocardiography of the ascending aorta. 16 flow velocities were recorded along the Doppler beam axis between the anterior and posterior aortic walls, and averaged over 8 beats. Flow times were derived from the flow curves and normalised by the ejection period as determined from the carotid pulse tracing. Thus, relative ejection time (% SEP) was calculated at the anterior (gate 4) and the posterior aortic wall (gate 13) as well as at the axis of the vessel (gate 9). In normals % SEP was 92 +/- 3% in gate 4, 95 +/- 4% in gate 9 and 93 +/- 3% in gate 13 (NS). In patients with HOCM % SEP was 92 +/- 5% in gate 4 and 83 +/- 4% (NS) in gate 9. At the posterior aortic wall (gate 13) % SEP amounted to 68 +/- 5% and was significantly lower than in gate 9 (P less than 0.05) and in gate 4 (P less than 0.001) respectively. It is concluded that in contrast to normals systolic flow time in hypertrophic obstructive cardiomyopathy varies along the sound beam in the ascending aorta. Flow time recorded at the posterior aortic wall is most abbreviated.

Abstract 2122: Head-to-head Comparison Between Tissue Doppler Imaging And Velocity Encoded Magnetic Resonance Imaging For The Measurement Of Myocardial Velocities And The Assessment Of Left Ventricular Dyssynchrony And Diastolic Function.

Aim of the study. To compare echocardiographic tissue Doppler imaging (TDI) and velocity encoded (VE) magnetic resonance imaging (MRI) for the measurement of myocardial velocities and the assessment of left ventricular (LV) dyssynchrony and diastolic function. Methods. Ten healthy volounteers (5 men, 31±5 yrs) and 25 heart failure (HF) pts (17 men, 58±11 yrs) underwent both cardiac MRI and TDI. Longitudinal myocardial peak systolic (PSV) and diastolic (PDV) velocities and time to PSV (Ts) and to PDV (Td) were measured at basal and mid level of LV septum and lateral wall. To quantify LV dyssynchrony, delay in Ts between basal septum and lateral wall was calculated (SLD) and pts were categorized in 3 groups according to the extent of LV dyssynchrony by TDI: minimal (SLD&lt;30 ms), intermediate (30 – 60 ms) and extensive (&gt;60 ms) LV dyssynchrony. As a measure of LV diastolic function, the ratio of transmitral E wave velocity and mitral annulus septal early velocity (E/E′) was also calculated and pts were classified in 3 groups: normal LV diastolic function (E/E′ &lt;8), abnormal LV diastolic function (E/E′= 8 –15) and severe LV diastolic dysfunction (E/E′&gt;15). Results. PSV measured with VE-MRI showed excellent correlation with PSV measured with TDI (r=0.94, P&lt;0.001) in both normals and HF pts and Bland-Altman analysis revealed a small bias (MRI-TDI) of 1±1 cm/s (P&lt; 0.001) between both techniques. A strong correlation was also observed between Ts measured with TDI and VE-MRI (r=0.97, P&lt;0.001) without significant bias. Excellent agreement between TDI and VE-MRI was found for LV dyssynchrony classification with a weighted κ=0.96. e′ and A′ PDV measured with VE-MRI correlated very well with PDV measured with TDI (r=0.95, P&lt;0.001) with a small bias of 0.4±1 cm/s (P&lt;0.001) between the 2 techniques. Excellent agreement between TDI and VE-MRI was also observed in classifying LV diastolic function with a weighted k=0.91. A very good correlation has been observed also for Td of E′(r=0.96, P&lt;0.001) and Td of A′ (r=0.88, P&lt;0.001) measured with both techniques. Conclusions. TDI and VE-MRI can be used interchangeably to measure LV myocardial systolic and diastolic velocities and excellent agreement exists between the 2 techniques for LV dyssynchrony and diastolic function classification.

Abstract 1602: Strain-derived and Tissue velocity-derived Dyssynchrony Indexes for Prediction of Reverse Remodeling with Cardiac Resynchronization Therapy

Background : Dyssynchrony indexes derived from time to peak systolic velocity and time to peak strain have been reported to predict left ventricular reverse remodeling (RR) after cardiac resynchronization therapy (CRT). The predictive characteristics of these indices have not been validated in a variety of clinical settings. Our objective was to determine the predictive value of strain and tissue velocity derived dyssynchrony indices for RR or clinical response to CRT in a prospective single-center CRT registry. Methods : Prospective registry of all heart failure patients (pts) undergoing CRT with echo before and 3 and 6 months after CRT. Color -coded tissue Doppler imaging in 12 segments was used to calculate the standard deviation of time to peak strain (Tϵ-SD) and time to peak systolic velocity (Tv-SD). RR was defined as a decrease in end systolic volume (ESV; biplane Simpson’s method) ≥15%. Indices were assessed with receiver-operating characteristics (ROC) analysis and the area under the curve (AUC) calculated in all pts and excluding those with atrial fibrillation at implant. Results : To date, of the first 87 patients, 4 died (classified as non-responder); 83 pts had 3 and 59 pts had 6 month echocardiography follow-up. Tϵ-SD (93%) and Tv-SD (98%) were feasible in most pts. RR occurred in 42 pts (51%) at 3 month and 32 patients (54%) at 6 month follow-up. See table . Tϵ-SD was superior to Tv-SD for prediction of RR in all pts and in those without atrial fibrillation. Findings were similar regardless of ischemic (68% of patients) or non-ischemic etiology. Neither baseline Tϵ-SD nor Tv-SD correlated with the improvement in clinical response measured by the change in six minute walk distance or peak VO 2 at 3 or 6 month after CRT (data not shown). Conclusions : In this single center experience, mechanical dyssynchrony measured by strain imaging but not tissue velocity imaging was predictive of RR. Neither index predicted clinical response.

Abstract 3340: Coronary Flow Velocity Pattern Immediately After Percutaneous Coronary Intervention Predicts Left Ventricular Remodeling in Patients with Acute Myocardial Infarction

Background: Studies using the Doppler guidewire have shown that coronary flow velocity (CFV) pattern in recanalized infracted arteries predicts recovery of regional left ventricular (LV) function, in-hospital complications, and long-term cardiac events. However, the relationship between the CFV pattern after reperfusion and serial changes in LV volumes is not clear. We postulated that the quantitative CFV measurement immediately after successful percutaneous coronary intervention (PCI) might be associated with the LV remodeling. To test this hypothesis, we prospectively analyzed the LV remodeling according to CFV parameters measured by the Doppler guidewire in patients with acute myocardial infarction (AMI). Methods: Consecutive 211 patients with first-time anterior AMI underwent successful PCI (&lt;50% residual stenosis with TIMI flow grade 2–3) and coronary flow measurement with the Doppler guidewire. The CFV spectrum provided the following parameters: time-averaged peak velocity (cm/s), systolic peak velocity (cm/s), and diastolic deceleration time (ms). Left ventriculograms obtained immediately after PCI and 6 months after the infarction were analyzed to measure the end-diastolic volume index and end-systolic volume index. The LV remodeling was defined as an increase in end-diastolic volume index ≥20%. Result: The optimal cutoff values to predict LV remodeling (defined as 6-month LV dilation ≥20%) were 20 cm/s for time-averaged peak velocity, 0 cm/s for systolic peak velocity and 550 ms for diastolic deceleration time (sensitivity=0.63, specificity=0.56; sensitivity=0.76, specificity=0.85; and sensitivity=0.85, specificity=0.85, respectively). Systolic peak velocity and diastolic deceleration time correlated to the LV end-diastolic volume index obtained 6 months after AMI(r= −0.67; p&lt;0.001 and r= −0.78; p&lt;0.001, respectively). Conclusions: The CFV pattern appears to be an accurate predictor of LV remodeling even in patients who received successful PCI in the left anterior descending coronary artery immediately after AMI. This index, therefore, identifies a subset of patients at-risk.

Quick adaptation of the myocardium and autonomic nervous regulation of the cardiac rhythm in 10- to 11-year-old children operating a computer

A study of quick adaptation of the myocardium of subjects operating a computer, depending on the adaptive capacities of the body, was conducted in 100 children with ages varying between 10 and 11 years using the electrocardiography method for the analysis of heart rate variability. Significant differences in the bioelectrical processes in the myocardium and autonomic nervous regulation of the cardiac rhythm (CR) were found in children with different adaptive capacities of the body. Quick adaptation to the operator activity in children with a good adaptive capacity is characterized by intensification of atrial activity and metabolic processes in the myocardium, as well as by a shortened duration of the cardiac cycle due to a shorter diastolic time, determined by increased sympathetic influences on the CR. In children with a decreased adaptive capacity, a decrease in the atrial excitability and myocardial metabolism, an increase in the systolic time, a decrease in the diastolic time, and an increase in parasympathetic influences on the CR are observed.

Continuous Renal Replacement Therapy With a Pulsatile Tubular Pump: Parameters Must Be Adjusted in Each Case

A three-valve, pulsatile tubular pump was used in 24 pigs weighing 10.2 +/- 3.2 kg; the pump was connected to a neonatal hemofiltration circuit. Ninety-two periods of 30 min were studied to analyze the efficacy of the system with variations in the percentage time in diastole, the diastolic speed, the systolic speed, and the percentage time in systole during which the postfilter valve was closed. System efficacy was determined by the blood flow through the filter, the ultrafiltrate volume, the vascular overload measured by the inlet aspiration pressure, and the filter overload measured by the cross-filter pressure drop and the transmembrane pressure. The variations in the pump parameters did not lead to significant differences in the efficacy of the system or in the vascular or filter overload. The parameters must be adjusted in each case to obtain the best yield with the lowest vascular and filter overload.

Editorial Comment on: Antioxidant Treatment Associated with Sildenafil Reduces Monocyte Activation and Markers of Endothelial Damage in Patients with Diabetic Erectile Dysfunction: A Double-Blind, Placebo-Controlled Study

Abstract Objective To investigate the synergic effect of propionyl L-carnitine (PLC) plus sildenafil in reducing monocyte oxidative activity and endothelial dysfunction markers in diabetic patients with erectile dysfunction (ED). Methods Thirty-two type 2 diabetic patients with ED (according to the International Index of Erectile Function-5 [IIEF-5]) were randomized to receive PLC (2g/d) alone ( n =8) or combined with sildenafil (50mg/d twice weekly) ( n =8), sildenafil alone (50mg/d twice weekly) ( n =8), or placebo ( n =8) in a double-blind, fixed-dose study. Monocyte oxidative activity (stimulation index [SI]), intercellular adhesion molecule-1 [ICAM-1], P-selectin, advanced glycation end product (AGE) levels, Doppler sonography (recording peak systolic velocity [PSV]; end diastolic velocity [EDV]; systolic wave time [SWT]; resistive index [RI]), and IIEF score were evaluated before and after 12 wk of treatment; IIEF-5 was evaluated again 4 wk posttreatment. Results SI was reduced by treatment with PLC alone or combined with sildenafil ( p p p p p p p =0.05). In patients on PLC treatment (with or without sildenafil), SI was correlated with IIEF-5 ( p p p Conclusion PLC plus sildenafil was more effective in reducing SI and endothelial dysfunction markers in patients with type 2 diabetes and ED.

A New Index of Endurance Fitness led from Cardiac Systolic and Diastolic Time

A New Index of Endurance Fitness led from Cardiac Systolic and Diastolic Time

2 Assessing ventricular function in patients with atrial fibrillation

The Frank-Starling law states that the stroke volume of a regular cardiac beat increases in response to an increase in the volume of blood filling the heart. If this law applies in atrial fibrillation (AF) as well as in sinus rhythm (SR) then cardiac function will depend on the duration of diastole in the preceding beat as well as the duration of the indexed beat. Aim: The aim of this thesis was to develop a series of tools which would allow an assessment of the changes in cardiac function from one beat to the next in AF and SR. A secondary aim was to find a means of describing rhythm in a way that reflected possible functional change. Methods: List-mode radionuclide ventriculography, RNVG, acquisitions of 373 patients in AF and a comparative group of 385 patients in SR were made. Software was written which allowed tightly defined preceding and indexed beat selection criteria to be established. Left ventricular ejection fraction (LVEF) and other functional parameters (pre-systolic volume, systolic time, the ratio of pre-systolic to end-diastolic volume, peak filling rate and first third filling fraction) were calculated for images created using different beat selection criteria based on the quartiles of beat length. Assessment used both variable and fixed time formatting and included a comparison of results achieved in the first and second half of the scan. Traditional linear measures of heart rate variability together with descriptors of the Poincar´e plot and cycle length entropy were used to describe rhythm in both AF and SR patients. Results: Substantial variation with indexed and preceding beat length was seen in both SR and AF in all the systolic parameters measured and in particular in LVEF where the standard deviation of LVEF for any one patient was found to be 8.2% in SR and 14.1% in AF. A combination of descriptors of rhythm was found to have good correlation with the range of LVEF measured. Examination of the results for LVEF in several clinical sub-groups suggests that the range of LVEF may have clinical interest. The techniques were applied in a small clinical study which considered the value of radio-frequency ablation in patients with AF and heart failure. In this study, measures of Sample entropy and the range of LVEF appeared to have prognostic value. Conclusion: A tool which allows the investigation of beat-to-beat functional variation in RNVG has been produced. It has been shown that the functional variation depending on beat selection criteria is substantial and may have clinical significance both in patients with underlying pathology and prognostically in patients undergoing radiofrequency ablation (RFA).