Early Diastolic Period Research Articles

Effects of Home-based Remote Cardiac Rehabilitation on Left Ventricular Function and Fear of Exercise in Patients after Percutaneous Coronary Intervention (PCI): A Retrospective Cohort Study

Aim: This study aims to explore the effects of home-based remote cardiac rehabilitation on left ventricular function and exercise fear in patients after percutaneous coronary intervention (PCI). Methods: A total of 232 patients with coronary heart disease after PCI treated in Tianshan Traditional Chinese Medicine Hospital from January 2020 to December 2022 were retrospectively analyzed. The patients were divided into the remote rehabilitation group (169 cases) and the routine group (63 cases) according to the exposure factor (home-based remote cardiac rehabilitation). Changes in left ventricular function and sports phobia Tampa Scale in patients with coronary heart disease after PCI were compared using propensity score matching to reduce selection bias and confounding factors. Results: After the intervention, the scores of patients in the tele-rehabilitation group were significantly higher than those in the conventional group in terms of fear of movement, perception of danger, fear of movement, avoidance of movement, and dysfunction (p-value < 0.05). Left heart function was compared between the tele-rehabilitation group and the conventional group. Patients in the tele-rehabilitation group had significantly higher peak mitral valve blood flow in the early diastolic period (E), peak mitral valve blood flow in the late diastolic period (A), six-minute walk test (6MWT), and ratio of the peak mitral valve blood flow in the early diastolic period to the peak mitral valve blood flow in the late diastolic period (E/A) than those in the conventional group (p-value < 0.05). However, the peak deceleration time and isovolumic diastolic time in the early mitral valve diastolic period were significantly higher in the tele-rehabilitation group than in the conventional group (p-value < 0.05). Conclusions: Home-based remote cardiac rehabilitation instruction can improve the heart function and exercise fear state of patients after PCI.

Effects and mechanism of Compound Qidan Formula on rats with HFpEF induced by hypertension and diabetes mellitus based on Ang Ⅱ/TGF-β1/Smads signaling pathway

Ethnopharmacological relevanceCompound Qidan Formula is composed of traditional Chinese herbs and has a good curative effect in the clinical application of cardiovascular diseases such as heart failure. However, its potential molecular mechanisms of action remain highly unknown. Aim of the studyTo observe the effect of Compound Qidan Formula on cardiac function in rats with HFpEF induced by hypertension and diabetes mellitus, and to explore its mechanism from Ang Ⅱ/TGF-β1/Smads signaling pathway. Materials and methodsA total of 50 SPF-grade spontaneously hypertensive rats (SHR) aged 14 weeks, fed with a high-fat and high-sucrose diet for 16 weeks, and after 2 weeks of a high-fat and high-sucrose diet, 1% streptozotocin (25 mg/kg body weight)was injected intraperitoneally to establish a rat model of HFpEF induced by hypertension and diabetes mellitus. After 8 weeks of intragastric administration, the changes in cardiac morphology and function were evaluated by echocardiography after anesthesia; the heart tissue was taken and embedded in paraffin for Masson staining, and the pathomorphological changes of left atrial tissue were observed under the optical microscope; the mRNA transcription levels of Ang Ⅱ, AT1R, TGF-β1, Smad2, Smad3, MMP-9 and TIMP-1in left atrial tissue of rats were detected by RT-PCR; and the protein expressions were detected by Western blot. ResultsCompared with the SHR-DM group, the QD-Low and QD-High groups significantly decreased the left atrial (LA) anteroposterior diameter and interventricular septal thickness (IVST) and improved the peak velocity of mitral valve blood flow in early diastolic period (E), maximum mitral valve blood flow in systolic period (A), mitral ring myocardial movement velocity in early diastolic period (e’) and E/e' ratio; the QD-High group significantly improved the E/A ratio, left atrial ejection fraction (LAEF) and left ventricular ejection fraction(LVEF). Masson staining showed that compared with the WKY group, the SHR-DM group had obvious myocardial histomorphological lesions. Compared with the SHR-DM group, the Compound Qidan Formula groups significantly improved cardiomyocyte hypertrophy and disordered arrangement and inhibited myocardial fibrosis; the mRNA expression levels of Ang Ⅱ, AT1R, TGF-β1, Smad2, Smad3, and MMP-9 in myocardial tissue of Compound Qidan Formula groups were significantly decreased, and the mRNA expression level of TIMP-1 was significantly increased. The protein expression levels of Ang Ⅱ, TGF-β1, P-Smad2/3, and MMP-9 were significantly decreased. ConclusionCompound Qidan Formula, composed of traditional Chinese herbs, can significantly improve cardiac function, improve atrial and ventricular remodeling, and prevent myocardial fibrosis and hypertrophy in rats with HFpEF induced by hypertension and diabetes mellitus. The mechanism may be related to regulating the Ang Ⅱ/TGF-β1/Smad2/3 signaling pathway.

Application of two dimensional speckle tracking imaging in the follow up of patients with coronary heart disease treated with metalol

Purpose: To investigate the application of two-dimensional speckle tracking imaging (2D-STI) in the follow-up of patients with coronary heart disease (CHD) who were treated with metalol. Methods: A total of 100 patients with CHD (CHD group) who were treated with metalol and had undergone percutaneous coronary intervention (PCI) at Tangshan Works’ Hospital, Tangshan, China, and another 100 healthy people (control group) were enrolled in this study. Prior to and after 6 months of treatment, echocardiography was performed on patients in control and CHD groups, respectively, and the wall motion score was calculated. The 2D-STI was used to obtain systolic peak longitudinal strain value (SLs), global peak longitudinal strain (GSL) and early diastolic peak longitudinal strain rate (SrLe) in the early diastolic period of 6 wall basal segments, middle segments, and apical segments of the left ventricle. Results: The wall motion score index (WMSI) of CHD group was higher than that of the control group, while the WMSI of CHD group after treatment was significantly lower than the value before treatment, (p < 0.05). In 2D-STI, the SLs, SrLe and GLS of patients after 6 months of treatment were significantly higher than those before treatment (p < 0.05).Conclusion: Thus, 2D-STI can be used to quantify the motion of the chamber wall and the effect of PCI surgery, and it also provides a stable new index and technique for evaluating the effects of treatment of CHD.

Utility of uterine artery doppler indices for prediction of preeclampsia: A narrative review with systematic analysis

Background: Hypertensive disorders complicating pregnancy are common. Preeclampsia and eclampsia are major causes of maternal morbidity and mortality, particularly in developing countries. With prompt recognition of symptoms and early diagnosis of preeclampsia can lead to improved maternal and neonatal outcomes. Although, numerous tests have been proposed for the prediction of preeclampsia, their results have been inconsistent. So, we focused our research to study the uterine artery doppler for predicting preeclampsia in high-risk women. Methodology: We conducted a search on Google Scholar and PubMed based on Medical Subject Heading terms preeclampsia and uterine artery Doppler ultrasound. The articles between 2016 and 2020 which were in English were taken into consideration. We performed a qualitative interpretation as an approach for extracting the data. Results: Majority of the studies showed raised pulsatility index as a good predictor of preeclampsia, although it was closely followed by uterine artery notching which is in the early diastolic period. Conclusion: The findings of our research suggest that uterine artery Doppler indices and early diastolic notch can be used as a tool for the prediction of preeclampsia with high confidence.

MECHANICAL PROPERTIES OF 3D-PRINTED BLOOD VESSELS

The demand for vascular substitutes in clinical practice has increased, and 3D-printed blood vessels could be advantageous alternatives. Determining the mechanical properties of 3D-printed blood vessels is important to further improve the technology and clinical application. Here, dogbone test samples with and without cells were generated by 3D printing with combined UV curing and hydrogel ion curing. Tensile tests were performed to measure the mechanical parameters of the dogbones and build two kinds of fluid–solid interaction models. In accordance with hydrodynamics and momentum theorems, the velocities in accelerated ejection period, ejection peak, reduced ejection period, and early diastolic period were selected as inlet velocities. Velocity distribution on the symmetry surface of the fluid and the stress and strain of the solid tube under different velocities were analyzed. Results reveal that the velocity decreases gradually from the fluid center to the wall. At a high inlet velocity, the fluid velocity is high, while the stress and strain of the wall increase. During cardiac ejection peak, the stress on the wall reaches the maximum value of 2018 Pa, which is much lower than the ultimate stress. In addition, the strength and stiffness decrease for the vessels added with cells. This work provides a feasible method for measuring the mechanical properties of 3D-printed blood vessels. Keywords: 3D printing, mechanical properties, fluid–solid interaction

Resting Coronary Blood Flow Velocity by Transthoracic Coronary Echocardiography is Higher in Patients with Cardiovascular Diseases Compared with the Healthy Adults

Transthoracic Coronary Echocardiography (TCE), defined as blood velocity detection mainly in the left anterior descending artery (LAD) by noninvasive Doppler echocardiography, has been employed to measure coronary blood flow velocity and coronary flow reserve in research labs and in clinical settings. Most prior studies focused on the coronary flow reserve data, and normal values for resting coronary artery flow velocity have rarely been reported. The purpose of this study was to examine resting coronary blood flow velocity in healthy subjects and patients with cardiovascular disease. We retrospectively collected resting coronary blood flow velocity data by TCE from 69 healthy subjects (42 M, 27 F, 60 ± 8 yrs) and 37 patients (27 M, 10 F, 63 ± 10 yrs) with various cardiovascular diseases (14 peripheral arterial disease, 5 Pre‐TAVR, 8 hypertrophy cardiomyopathy, 10 CABG). The patient group had higher systolic blood pressure (135 ± 18 vs. 120±14 mmHg, P value <0.001), mean blood pressure (94 ± 11 vs. 89 ±10 mmHg, P value <0.05), and Rate‐Pressure Product (RPP, an index of myocardial oxygen demand) (8617 ± 1702 vs. 7249 ± 1453. P value < 0.001). Resting coronary blood flow velocities early (CBV1) and late (CBV2) in diastole were significantly higher in the patient group (CBV1: 27.6±8.6 vs. 19.0 ± 4.9 cm/s, P value < 0.001; CBV2: 17.6 ± 5.5 vs. 13.4 ± 3.2 cm/s, P value <0.001). After controlling for oxygen consumption (CBV/RPP), resting coronary blood flow velocity during the early diastolic period was still significantly higher in patients than in the healthy group (Adjusted CBV1: 3.3 ± 1.4 vs. 2.7 ± 0.8 au, P value < 0.001). There was no significant difference in adjusted coronary blood flow velocity during the late diastolic period (Patient group vs. healthy group, 2.1 ± 0.8 vs.1.9 ± 0.5 au, P value = 0.105). Further studies are needed to explore the clinical implication and importance of higher resting coronary blood flow velocity data by TCE in patients.Support or Funding InformationSupported by National Institutes of Health Grants P01 HL134609 (Sinoway), and UL1 TR002014 (Sinoway).This abstract is from the Experimental Biology 2019 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.

Diastolic Stunning as a Marker of Severe Coronary Artery Stenosis: Analysis by Speckle Tracking Radial Strain in the Resting Echocardiogram.

Two-dimensional speckle tracking (2DST) stress echocardiography detects postischemic myocardial diastolic stunning. However, the use of 2DST at rest for detecting diastolic stunning in ischemia is unclear. Thirty-nine patients (age = 65 ± 12 years; male/female = 34/5) with effort angina pectoris that was confirmed by stress myocardial perfusion scintigraphy were enrolled. Ischemic area (I) was determined in the middle LV short axial view using stress myocardial scintigraphy. The area opposite to it was defined as nonischemic area (non-I). Midventricular parasternal short-axis (SAX) radial strains were estimated using 2DST at rest on the following day. LV diastolic function was evaluated using diastolic index (DI, changes in the regional LV radial strain during diastole) and radial strain rate (SR) during early diastolic period. These parameters were compared between I and non-I before and 1 month after percutaneous coronary intervention (PCI) in the I of 3 coronary vessels. For the I, the DI was lower (38 ± 27 vs. 55 ± 27; P = 0.003) and SR was higher (-1.6 ± 0.6 vs. -1.9 ± 0.8; P = 0.007) than in non-I before PCI. One month after PCI, the DI and SR recovered to 53 ± 27 (P = 0.008) and -2.1 ± 0.8 (P = 0.006), respectively. Furthermore, the DI of the LAD and LCX significantly improved (P = 0.0004 and 0.002, respectively); the RCA area showed tendency to improve (P = 0.092), and the SR also improved (P < 0.05) in all areas after PCI. Diastolic stunning in ischemic areas can be detected using 2DST at rest and recover 1 month after PCI.

Left ventricular longitudinal rotation changes in primary hypertension patients with normal left ventricular ejection fraction detected by two-dimensional speckle tracking imaging.

In order to assess the left ventricular (LV) longitudinal rotation (LR) in primary hypertension (PH) patients with a normal LV ejection fraction. Conventional echocardiography was performed in 61 healthy subjects and 64 PH patients. The apical four-chamber views in these patients were acquired by GE-Vivid7 or E9, then the peak radial strain in the systolic period and the strain rate in systole, in early and late diastolic periods, were measured. Segmental LR and global LR were assessed by using two-dimensional speckle tracking imaging (2D-STI). The peak radial strain rate in the early diastolic period in PH patients was significantly lower than that in healthy subjects. The rotational degrees of the middle and base lateral, the apex and the middle septum walls in PH patients were significantly different from those of the healthy subjects. The healthy subjects had prominent counter-clockwise LR (0.29°±2.86°) and the PH patients had prominent clockwise LR (-2.13°±2.93°) in non-LV wall hypertrophy and (-2.43°±2.66°) in LV wall hypertrophy. The time delay between the LV lateral wall and the septum wall in PH patients correlated to the peak LR. We concluded that 2D-STI can assess the time delay between the LV lateral wall and the septum wall to the peak LR and clockwise LR in patients with PH, and prove that PH patients have a clockwise LR. By this, we conclude that in PH patients, the LV early systolic function have changed.

Incidence and fate of the abnormal septal motion after open heart surgeries.

REFER TO THE PAGE 8-13 Abnormal septal motion (ASM), or septal bouncing, is a paradoxical bouncing motion of the interventricular septum.1) During early diastolic period, interventricular septum initially directed towards and moves away from the left ventricle. ASM can be found frequently during echocardiographic examinations. If physician or echocardiographer found ASM during their studies, they should bear in mind the causative etiologies including constrictive pericarditis, pericardial tamponade, pulmonary hypertension, septal ischemia, left bundle branch block, congenital absence of pericardium and right ventricular pacing.2),3),4),5),6) Although they showed similar echocardiographic finding of ASM, their clinical presentations and managements were totally different. Some of them can be differentiate easily. However, some of them should be diagnosed to give appropriate and timely treatment. Of them, constrictive pericarditis is the most important etiology should be ruled out. In one study, sensitivity and specificity of ASM in the detection of constrictive pericarditis were 62% and 93%.7) They also reported that the presence of vena caval plethora and pericardial adhesion were other echocardiographic findings of constrictive pericarditis and ASM was the most consistent finding among examiners. ASM can be also seen in patients underwent pericardiotomy during open heart surgery.8) In the previous study, they showed the incidence of ASM after open heart surgery retrospectively and they found valve surgery is more likely to cause ASM than coronary artery bypass surgery. In this study, the authors demonstrated the incidence of ASM with regular follow-ups, prospectively.9) There was no report about the chronological sequence of ASM in patients with open heart surgeries. The authors serially checked the incidence and fate of ASM in patients underwent open heart surgery.9) Interestingly, it appeared about 70% of patients immediately after the open heart surgery. The presence of ASM was associated with lower left ventricular ejection fraction and late mitral filling velocity. However, the authors showed ASM was not associated with myocardial ischemia and disappears with time (25% at 3--6 months and 15% after 1 year). The incidence of ASM in this study was much lower than that of previous report by Reynolds et al.8) However, their result was a retrospective study and there was inhomogenous time-interval of the postoperative echocardiographic study. Because the authors showed the chronological sequence of ASM in patients underwent open heart surgery prospectively, the manuscript showed unique finding with exact incidence of ASM.9) There are several proposed mechanisms of ASM including the injury of interventricular septum during the surgery and the pericardial incision. Although there was no difference between coronary artery bypass surgery and valvular heart surgery in this study, this study showed ischemia of interventricular septum during open heart surgery is not a causative mechanism. Pericardial incision can cause pericardial adhesion and can result in ASM. This study found relatively high incidence of ASM immediately after the open heart surgery. This result indicated that ASM can be associated with the pericardial incision and resultant acute pericardial inflammation, immediately. As pericardial inflammation resolved gradually, the incidence of ASM decreased. However, the persistent ASM after 1 year might be associated with the pericardial adhesion. However, this manuscript has several limitations. First, the study population was small to show the difference of incidence according to the etiology like previous study. The authors also mentioned this in the limitation part. If they increase the number of patients with strict regular follow-up echocardiographic examination, the results may be more informative in the decision making of the postoperative ASM. Morever, the authors did not compare the persistent ASM and transient ASM groups. If they found and showed the difference between two groups, readers may wait the disappearance of ASM with comfort based on their results. Because the etiologies of ASM after open heart surgeries can be diverse, prospective studies with a large numbers of patients and a reliable imaging study of pericardial inflammation should be needed.

Left ventricle enlargement and increased systolic velocity in the mitral valve are indirect markers of the hepatopulmonary syndrome

Hepatopulmonary syndrome (HPS) has been associated with left atrial enlargement, but the presence of other markers of left and right diastolic and/or systolic cardiac dysfunction has not been clarified. We prospectively evaluated the possible associations between echocardiographical-Doppler findings and HPS. Seventy-nine cirrhotic patients without endogenous heart or pulmonary disease were included. HPS was diagnosed by the presence of increased arterial-alveolar-difference and intrapulmonary right-to-left shunt at contrast-enhanced transthoracic echocardiography. Echocardiographical systolic and diastolic indices, tissue Doppler imaging (TDI) of mitral and tricuspid annular motion and M-mode echocardiography measurements were recorded. Hepatopulmonary syndrome was diagnosed in 12 (15.2%) patients. Patients with compared with those without HPS had significantly younger age, albumin levels and saturation of oxygen (SaO(2)) in an erect position, but higher left ventricular end diastolic diameter (LVEDD), ejection fraction, E-wave peak velocity of tricuspid valve, left atrial volume, TDI E wave (early diastolic period) at the right free wall/tricuspid annulus (cm/s) and TDI S wave (systolic) at the left lateral wall/mitral annulus (TDI Smv). In multivariate analysis, the presence of HPS was found to be independently associated with younger age (P=0.027), lower SaO(2) in an erect position (P=0.023), higher LVEDD (P=0.019) and higher TDI Smv (P=0.026). LVEDD and TDI Smv offered good diagnostic accuracy for HPS diagnosis (AUROC/c-statistic: 0.724 and 0.736 respectively). We confirmed that in patients with cirrhosis, the development of HPS is associated with higher cardiac output and hyperdynamic circulation. Left ventricle enlargement and higher systolic velocity in the mitral valve represent satisfactory indirect markers of HPS.

SR Ca 2+ store refill—a key factor in cardiac pacemaking

This study presents a theoretical analysis of the role of store Ca 2+ uptake on sinoatrial node (SAN) cell pacemaking. Two mechanisms have been shown to be involved in SAN pacemaking, these being: 1) the membrane oscillator model where rhythm generation is based on the interaction of voltage-dependent membrane ion channels and, 2) the store oscillator model where cyclical release of Ca 2+ from intracellular Ca 2+ stores depolarizes the membrane through activation of the sodium-calcium exchanger (NCX). The relative roles of these oscillators in generation and modulation of pacemaker rate have been vigorously debated and have many consequences. The main new outcomes of our study are: 1) uptake of Ca 2+ by intracellular Ca 2+ stores increases the maximum diastolic potential (MDP) by reducing the cytosolic Ca 2+ concentration [Ca 2+] c and hence decreasing the NCX current; 2) this hyperpolarization enhances recruitment of key pacemaker currents (e.g. the hyperpolarization-activated HCN current ( I f) and T-type Ca 2+ current ( I T-Ca)); 3) the resultant enhanced Ca 2+ entry during the pacemaker depolarization increases [Ca 2+] c causing advancement of the store Ca 2+ release cycle and increased NCX current. In overview, the novel feature of our study is an investigation of the role of store Ca 2+ uptake on SAN pacemaking. This occurs during the early diastolic period and causes enhanced I f, I T-Ca and store release (and hence I NCX) during the later diastolic period. There is thus a symbiotic interaction between the two pacemaker “clocks” over the entire diastolic period, this providing robust and highly malleable SAN pacemaking. Accounting for store Ca 2+ uptake also provides insight into hitherto unexplained SAN behaviour, as we exemplify for the sinus bradycardia exhibited in catecholaminergic polymorphic ventricular tachycardia (CPVT).

Assessment of left ventricular torsion in patients after coronary artery bypass graft by velocity vector imaging

Objective To evaluate left ventricular torsion in patients after coronary artery bypass graft(CABG) surgery by velocity vector imaging(VVI). Methods Twelve patients who were scheduled to have CABG surgery were enrolled. VVI offline software was used to evaluate myocardial rotation in both basal and apical segment before and three months after CABG. The rotation and rotation rate of each a counterclockwise rotation at the apex and a clockwise rotation at the base, and the absolute value of CABG the rotation at the base was significantly improved than that before CABG (P <0.001), and the rotation in the segment of anterior septum, anterior wail and inferior septum at the base was higher than that rotation in the apical and basal segment three months after CABG was also significantly higher than that negative peak rotation rate in the early diastolic period at the apex were significantly higher than those at the improved than that before CABG (P <0.001). And the positive peak rotation of the systolic period in the segment of anterior septum,anterior wall,lateral wall and inferior septum and the negative peak rotation of the diastolic period in the segment of anterior and inferior septum at the base were also higher than those before CABG (P <0.001). Conclusions VVI is a useful method which can quantitatively assess left ventrieular torsion in patients before and after CABG surgery. Key words: Eehocardiography; Coronary artery bypass; Ventricular function,left; Torsion

Mutant MiRP1 subunits modulate HERG K+ channel gating: a mechanism for pro-arrhythmia in long QT syndrome type 6.

Mutations in KCNE2, which encodes the minK-related protein 1 (MiRP1), are associated with an increased risk of arrhythmias; however, the underlying mechanisms are unknown. MiRP1 is thought to associate with many K+ channel alpha-subunits, including HERG K+ channels, which have a major role in suppressing arrhythmias initiated by premature beats. In this study we have investigated in Chinese hamster ovary (CHO) cells at 37 degrees C the effects of co-expressing HERG K+ channels with either wild-type (WT) MiRP1 or one of three mutant MiRP1 subunits, T8A, Q9E and M54T. The most significant effects of MiRP1 subunits on HERG channels were a more negative steady-state activation for HERG + T8A MiRP1 and a more positive steady-state activation for HERG + M54T MiRP1 compared to either HERG + WT MiRP1 or HERG alone. All three mutants caused a significant slowing of deactivation at depolarised potentials. T8A MiRP1 also caused an acceleration of inactivation and recovery from inactivation compared to HERG + WT MiRP1. During ventricular action potential clamp experiments there was a significant decrease in current in the early phases of the action potential for HERG + WT MiRP1 channels compared to HERG alone. This effect was not as prominent for the mutant MiRP1 subunits. During premature action potential clamp protocols, the T8A and Q9E mutants, but not the M54T mutant, resulted in significantly larger current spikes during closely coupled premature beats, compared to HERG + WT MiRP1. At longer coupling intervals, all three mutants resulted in larger current spikes than HERG alone or HERG + WT MiRP1 channels. It is therefore possible that augmentation of HERG currents in the early diastolic period may be pro-arrhythmic.

Ionic mechanisms of the cardiac pacemaker potential.

The experimental evidence so far described in the literature is reviewed to explain the ionic mechanisms underlying the cardiac pacemaker potential in the sinoatrial node cell. Following gating mechanisms underlie the slow diastolic depolarization of the SA node cells. The delayed rectifier K+ channels (mainly the rapidly activated component of the delayed rectifier K+ currents, which is blocked by E-4031) activated during the preceding action potential are deactivated during diastole. The inactivation of the L-type Ca2+ channel is removed during the early diastolic period and results in an increasing inward current, provided that the amplitude of the window component is of significant amplitude. Because of its sustained nature, the removal of inactivation of the sustained inward current Ist, also generates inward current. The negative membrane potential near the maximum diastolic potential activates the hyperpolarization-activated non-selective cation current, I(f). Finally, the L-type Ca2+ channel is activated at the late phase of diastole depolarization, resulting in the maximum rate of rise of the action potential. These time- and voltage-dependent changes in membrane conductance occur in the presence of a significant background conductance. During the slow diastolic depolarization, Ist and IK may be the major component in the inward and outward currents, respectively.

Pulsed Doppler echocardiographic indices of left ventricular diastolic function in normal subjects.

To establish the normal limits for various pulsed Doppler echocardiographic indices of left ventricular diastolic function, 92 healthy volunteers aged from 5 to 75 years were prospectively studied. The influence of various variables including age, gender, body surface area, fractional shortening, and left ventricular mass on these parameters was also assessed. Mean (2SD) values for 15 direct and 11 derived parameters were analyzed from transmitral inflow velocity waveform. No statistically significant differences were observed between males and females for any of these parameters. On stepwise multivariate linear regression analysis, age was found to be an independent strong determinant (p less than 0.001) of peak velocity of early diastolic filling wave, area of atrial filling period, deceleration slope, normalized peak filling rate, and early filling fraction. There was a significant correlation between heart rate and time to peak early diastolic velocity, total diastolic time period, early diastolic period, atrial filling period, and atrial filling fraction. It was further observed that a significant correlation (p less than 0.001) persisted between both age and heart rate with area of early filling period, one-third filling area, one-half filling area, ratio of early to atrial peak velocity and area, atrial filling fraction, and one-third filling fraction. None of the parameters were found to correlate with fractional shortening or left ventricular mass. Thus an effort was made to establish normal limits for various Doppler-derived parameters in healthy volunteers for future comparison in diseased states.(ABSTRACT TRUNCATED AT 250 WORDS)

Cineangiographic evaluation of diastolic properties of the left ventricle in man.

Diastolic properties of the left ventricle were evaluated cineangiographically in 110 patients with various heart diseases (19 normal cases, 13 mitral stenosis, 19 left ventricular volume overload, 18 coronary artery diseases without myocardial infarction, 27 myocardial infarction, 6 hypertrophic cardiomyopathy, 5 congestive cardiomyopathy and 3 chronic constrictive pericarditis). Early diastolic ventricular filling was assessed by diastolic maximal circumferential relaxation velocity (maxVcf), diastolic maximal dV/dt, volume change during early 1/3 of ventricular filling (V1/3), rapid filling time and isovolumic relaxation time; myocardial stiffness constant K was calculated at end-diastole. Increase in myocardial stiffness constant was not necessarily associated with abnormal indices measured during the early diastolic period but well correlate with isovolumic relaxation time. During the isovolumic relaxation period, the affected left ventricular segments where myocardial infarction or myocardial hypertrophy existed, showed reduced and delayed relaxation resulting in a total increase in the isovolumic relaxation period. Calcium antagonist was effective in improving the delayed relaxation in patients with left ventricular hypertrophy, suggesting a role of calcium on delayed myocardial relaxation in the hypertrophied heart.

Clinical significance of early diastolic changes in left ventricular wall thickness.

Continuous measurement of posterior left ventricular wall thickness on one or two-dimensional echocardiograms or left ventriculograms has demonstrated an early diastolic period of rapid thinning at a peak rate of 10 ± 1.7 cm/s, significantly greater than the peak thickening rate during systole. In normal subjects, this period ends abruptly, and is coterminous with rapid filling. Thinning rates are greatest at the level of the tips of the papillary muscles, and are significantly lower towards the mitral ring. In patients with ischaemic heart disease, mitral valve opening may be delayed until rapid thinning is complete, showing that it is not a function of left ventricular filling, and therefore likely to be a manifestation of relaxation itself. Thinning rate is reduced in patients with left ventricular hypertrophy due to hypertension, aortic stenosis or hypertrophic cardiomyopathy, when it is associated with a corresponding reduction in the peak rate of dimension increase. It persists when the cause of the hypertrophy is removed as after resection of coarctation of the aorta, even if wall thickness returns to normal. Variation in peak rapid thinning rate with position in the cavity appears to underly abnormal filling patterns in pure mitral regurgitation, and determines the distribution of abnormal wall movement during isovolumic relaxation in patients with coronary artery disease. This distribution also correlates with fibre orientation in normal human hearts as demonstrated by dissection. The period of rapid thinning is associated with intraventricular pressure gradients. It is also exactly synchronous with the early diastolic period when calculated wall stress remains constant in spite of increasing cavity size, an effect that has previously been attributed to viscosity. We conclude that rapid early diastolic wall thinning depends on the integrity of regional fibre arrangement, and is a major determinant of the rate and pattern of the rapid phase of left ventricular filling in normals. Its loss causes disturbances of wall movement during relaxation and filling in disease.

Left Ventricular Diastolic Properties in Man with Special Reference to the Early Diastolic Period

Cineangiograms of 20 patients were analyzed with a computer to calculate instantaneous left ventricular volume and the rate of volume change (dV/dt, flow) for a cardiac cycle. Patients were divided into four groups : group I-normal, group II-mitral stenosis, group III-left ventricular volume overload, and group IV-coronary artery disease. The instantaneous flow (ordinate) -volume (abscissa) relationship showed a loop which rotated in a counterclockwise direction accompanied by rapid downslopes during early diastole in groups I and III. The steepness of the early diastolic downslope was markedly decreased in groups II and IV. In order to evaluate the findings numerically, flow at the early 20% of diastolic volume change (F20), F20 corrected with peak diastolic flow (F20/Fd) and F20 corrected with peak systolic flow (F20/Fs) were measured. F20/Fs and F20/Fd were significantly lower in groups II and IV than in groups I and III. On the other hand, stiffness constant obtained during later diastole stayed within normal limits in groups I and II, but the index was increased in groups III and IV. Possible mechanism for the decreased flow during early diastole, i.e., delayed relaxation during early diastole in groups II and IV, and dissociation between early diastolic relaxation and the stiffness constant obtained during later diastole in groups II and III are discussed.

The functional anatomy of ventricular contraction.

Changes in dimensions of the ventricular chambers and the displacement of specific points on the walls of the heart have been studied by the cinefluorographic technic. The contributions of the various myocardial layers to ventricular ejection have been considered in terms of the anatomic architecture of the heart. The mechanical effectiveness of myocardial contraction is closely related to the degree of diastolic distension and the magnitude of the stroke volume. During contraction, the various layers must exert tension on the connections between them. Energy expended in this manner does not contribute to ventricular ejection but could theoretically promote rapid filling during the early diastolic period.

APICAL DIASTOLIC HEART SOUNDS IN ACTIVE RHEUMATIC FEVER

Of 400 children under observation during active rheumatic fever, 115, or 29%, presented either an apical diastolic third sound or an early apical diastolic murmur. Of these, 54, or 49%, were found to have an apical diastolic third heart sound and an early diastolic apical murmur in some sequence. The rapid flow of blood from auricles to ventricles during the early diastolic period of the cardiac cycle is thought to be the primary factor responsible for both the third heart sound and the early diastolic murmur. Factors which tend to increase intra-auricular pressure, such as regurgitation at the mitral valve, favor rapid blood flow through the auriculo-ventricular valves and production of these sounds. The importance of the apical diastolic murmur as a sign of myocarditis per se is discussed.