Left ventricular diastolic function: Physiology,methods of assessment,and clinical significance

Diastole, that portion of the cardiac cycle that begins with isovolumic relaxation and ends with mitral valve closure, results in ventricular filling and involves both active (energy-dependent) and passive processes. The interactions between active processes (myocardial relaxation) that primarily influence early ventricular filling and passive processes, such as loading conditions, myocardial compliance, and valvular disease, are complex. Clinical methods to assess ventricular filling include cardiac catheterization, radionuclide angiography, and echocardiography. Any measurements of diastolic function must be made with an understanding of the determinants of ventricular filling and the limitations of the diagnostic test. Many cardiac disorders are characterized by elevated pulmonary venous pressures in the face of normal systolic ventricular function, which suggests a primary abnormality of diastolic function. Abnormalities in diastolic function have been observed in coronary artery disease, congestive heart failure (with and without systolic dysfunction), hypertrophic cardiomyopathy, hypertension, and in healthy elderly subjects. Identification of these abnormalities may be useful clinically, particularly in patients with symptoms of heart failure and normal systolic function. Data are not available to determine the optimal therapy for such patients, although evidence suggests that calcium channel blockers, beta blockers, and agents that reverse myocardial hypertrophy may be useful. This review briefly summarizes the physiology of diastole, the methods of clinical assessment of diastolic function, and the role of diastolic function in cardiovascular disease.     

超声心动图对胎儿主动脉弓峡部血流的频谱分析

目的探讨超声心动图对胎儿主动脉弓峡部血流的频谱分析价值。方法选取我院孕妇156例,行超声心动图检查主动脉峡部内径、血流速度、搏动指数、阻力指数及胎儿左心室排血量、右心室排血量、动脉导管流量以及主动峡部流量情况,并分析上述检测参数与孕周的相关性。结果孕周与峡部内径、收缩早起流速、收缩末期流速、舒张早期流速、舒张中期流速、舒张末期流速、PI、RI呈正相关关系。孕周与胎儿左心室排血量、右心室排血量、联合心输出量、主动脉峡部血流、动脉导管流量呈正相关关系。回归方程结果显示:孕周与峡部内径、收缩早起流速、收缩末期流速、舒张早期流速、舒张中期流速、舒张末期流速、PI、RI拟合程度相对较差,与胎儿左心室排血量、右心室排血量、联合心输出量、主动脉峡部血流、动脉导管流量拟合程度较好。结论正常胎儿超声心动图检查主动脉血流频谱各参数与孕周呈现正相关,其能够为诊断胎儿血流异常提供帮助。     

Estimation of the left ventricular diastolic function with cardiac MDCT: correlation of the slope of the time-enhancement-curve with the mitral annulus diastolic velocity

Patients with diastolic heart failure tend to have a poor outcome, similar to that for patients with systolic heart failure. The aim of this study was to explore the ability of MDCT to estimate the left ventricular diastolic function. Thirty patients with suspected coronary artery disease underwent MDCT and echocardiography. The early transmitral flow velocities (E) and the velocity of mitral annulus early diastolic motion (e') were measured in order to evaluate the diastolic function. The scanning delay of CT was determined using a test injection technique. The aortic enhancement was measured over the aortic-root lumen, and it was plotted over time to yield a time-enhancement-curve. A gamma variate function was then fit to the time-enhancement-curve and thereafter both the 'slope' of enhancement for each patient and the region of interest [ROI] were calculated. According to a univariate analysis, the slope of the time-enhancement-curve was found to correlate with the e' (r = 0.686, P = 0.000) and E/e' (r = -0.482, P = 0.007), however, no significant correlation was observed with the systolic parameters of the left ventricle. These results indicate that the slope of the time-enhancement-curve in the aorta significantly correlates with e', i.e. the diastolic parameters, which are independent of the systolic parameters. Based on these findings, we propose that the slope of the time-enhancement-curve may serve as a parameter for the left ventricular diastolic function on MDCT.     

胸痛患者多巴酚丁胺负荷超声心动图的左心功能变化

目的　探讨胸痛患者在多巴酚丁胺负荷超声心动图 (DSE)情况下的左心功能变化。方法　采用二维、脉冲式多普勒超声检测DSE患者左室收缩和舒张功能。结果　 18名胸痛患者 ,经DSE后 ,出现左室壁局部运动异常 8例 (DSE阳性患者 ) ,左室壁普遍性运动增强 10例 (DSE阴性患者 )。DSE阴性患者的每搏量 (SV)、心输出量 (CO)明显高于DSE阳性患者 (P <0 .0 5 ) ;多巴酚丁胺峰值剂量时E/A比值两组患者均 <1。结论　DSE可作为胸痛患者左室局部、整体收缩功能的较好评估方法 ,而对左室舒张功能的判定尚缺乏合适的指标     

Diastolic dysfunction types in the prediction of viable myocardium functional recovery

BACKGROUND/AIM: It is well known that patients with coronary artery disease and viable tissue as a guarantee of contractile recovery (CR), despite of decreasing ejection fraction (EF) and systolic dysfunction, could have benefit from surgical revascularization. Therefore, relationship between diastolic filling type and early postoperative recovery and complications need to be established. The aim of this study was to investigate the relation between different left ventricular (LV) diastolic filling types and CR in patients after surgical revascularization with differently preserved systolic function. METHODS: We investigated 60 patients. All of them had CR estimated by stress echocardiography regardless the extent of recovery of the heart systolic function. Echocardiographic evidence of diastolic dysfunction was estimated by Doppler examination of transmitral diastolic flow. According to the derived different diastolic filling types the patients were divided into three groups: I--patients with disorder of LV relaxation, II--with pseudovascularisation, and III--with restrictive filling type, and according to the value of systolic function into two subgroups: (1) relatively recovered systolic function--EF > 40% and (2) pronounced LV dysfunction--EF < 40%. Echocardiographic evaluation was performed before and two week after surgical revascularization. In the preoperative period the medication therapy was optimized. We estimated CR by echocardiografic pare meters but also by detection of cardiovascular events. RESULTS: After CABG the mean value of WMISI LV tended to decrease in any groups: in the group I (n = 12) from 1.64 +/- 0.22 to 1.34 +/- 0.22; in the group II (n = 22) from 1.85 +/- 0.16 to 1.53 +/- 0.42, and in the group III (n=26) from 1.92 +/- 0.29 to 1.81 +/- 0.52. The lowest improvement of systolic function according to EF value expressed by the number of patients was found in the group of patients with restrictive LV filling type (12; 53.8%) as contrasting to the group with pseudonormalisation (15; 78.9%). In the group of patients with restrictive diastolic filling type also was recorded the highest number of lethal outcomes (6; 23.1%), as well as cardiovascular complications (10; 38.5%). CONCLUSIONS: Restrictive LV diastolic filling type was the marker of poor prognosis in the patients with clinical heart failure undergoing surgical revascularization. The patients with heart failure and preserved systolic function were associated with similar prognosis.     

射血分数正常心力衰竭的超声心动图指标与中医辨证分型的相关性研究

目的:探讨射血分数正常心力衰竭(heart failure with normal ejection fraction,HFNEF)患者中医辨证分型与超声心动图指标的相关性。方法:将我院收治的118例HFNEF患者分为心气阴虚证、心肾阳虚证、气虚血瘀证、阳虚水泛证4组,对各证型的超声心动图指标及实验室指标血浆B型钠尿肽(BNP)数据行统计学分析。结果:HFNEF患者各证型的年龄和心功能分级构成比差异有统计学意义,心气阴虚证、心肾阳虚证、气虚血瘀证、阳虚水泛证4组心功能呈逐渐减低趋势;各证型患者均有心脏收缩和舒张功能的异常,其中左房容积指数、二尖瓣环收缩期平均速度(s’mean)、二尖瓣环舒张晚期峰值速度(a’mean)、舒张早期二尖瓣口血流速与二尖瓣环平均速度比(E/e’mean)和血浆B型钠尿肽差异有统计学意义(P0.05)。结论:HFNEF的中医证型与超声心动图指标及血浆BNP具有一定的相关性,超声心动图可作为中医辨证分型的客观量化指标。     

Carotid duplex sonography: bisferious pulse contour in patients with aortic valvular disease.

Characteristic systolic and diastolic pulse contours occur in the carotid Doppler waveforms of patients with aortic valvular disease that have not previously been described in publications concerning carotid duplex sonography. The purpose of this study was to evaluate the presence and characterize the nature of these carotid duplex waveform abnormalities in patients with known aortic valve disease and to correlate these changes with the severity of valve dysfunction. The study group consisted of 26 patients with aortic regurgitation or combined aortic regurgitation and aortic stenosis. Duplex studies were retrospectively reviewed by two radiologists for the presence of two systolic peaks, and for the presence of diastolic reversal of flow direction. This pattern of two systolic peaks, characteristic of aortic regurgitation, is called bisferious from the Latin "twice beating." Aortic regurgitation was graded by echocardiography as mild, moderate, or severe by the cardiologists reviewing the examination. A group of 20 age-matched patients without aortic valvular disease were similarly assessed. The bisferious pattern was demonstrated in 13 (50%) of 26 patients. Five (19%) of 26 patients had significant reversal of diastolic flow. Four patients were studied both before and after aortic valve replacement. Three had bisferious wave contours preoperatively; two of these also had diastolic reversal of flow. The fourth patient had retrograde flow in diastole without systolic contour abnormality. Postoperatively, all carotid waveforms were normal. None of the duplex waveforms in the control group demonstrated characteristic systolic or diastolic abnormalities. The bisferious waveform and retrograde diastolic flow are Doppler patterns associated with aortic valvular disease. These patterns are reversible after aortic valve replacement. While echocardiography remains the study of choice in the evaluation of suspected valvular dysfunction, up to one third of patients with aortic regurgitation may not have a detectable murmur. Therefore, identifying these patterns on carotid duplex examinations may provide clinically useful information and serve as a clue to previously unsuspected cardiovascular disease.     

Assessment of left ventricular diastolic function by gated single-photon emission tomography: comparison with Doppler echocardiography

Gated single-photon emission tomography (SPET) is not yet an established procedure for the evaluation of left ventricular (LV) diastolic function. This study examined diastolic function derived from gated SPET in comparison with an established diagnostic tool, Doppler echocardiography. We examined 37 consecutive patients with normal sinus rhythm who underwent gated technetium-99m tetrofosmin SPET. A gated SPET program was used with a temporal resolution of 32 frames per R-R interval. We obtained the Doppler transmitral flow velocity waveform immediately before gated SPET image acquisition. Patients who showed a ratio of peak early transmitral flow velocity to atrial flow velocity (E/A) of >1 or whose R-R intervals differed by >5% between Doppler echocardiography and gated SPET were excluded from this investigation. We compared diastolic indices and presumed corresponding intervals in diastole using the two methods. The peak filling rate (PFR) derived from gated SPET correlated with the Doppler peak velocity of the early transmitral flow (E) wave (r=0.65) and deceleration of the E wave (r=0.71). The time to PFR and percent atrial contribution to LV filling from gated SPET correlated excellently with the Doppler LV isovolumic relaxation time (r=0.93) and the E/A ratio (r=–0.85), respectively. There was a significant linear correlation in all the intervals from the R wave to the presumed corresponding diastolic points. The point of PFR in gated SPET and the peak of the E wave in Doppler echocardiography generally coincided. The onset of filling in gated SPET tended to be closer to the second heart sound than the start of the E wave in Doppler echocardiography. We conclude that gated SPET permits the assessment of not only myocardial perfusion and LV systolic function but also diastolic function, although there may be some errors in detection of the precise beginning of LV filling.     

组织多普勒成像技术评价冠心病心肌梗死后左室整体功能

 目的 应用超声心动图对冠心病心肌梗死患者进行检测,寻找与左室功能相关性良好的指标以利于临床评估.方法 对经临床及冠状动脉造影确诊的心肌梗死(1～6个月)患者68例行多普勒超声心动图检查.根据其二尖瓣口血流频谱形态将患者分为3组:左室松弛性减低组、假性正常化组、限制性充盈组;又根据心脏射血分数(ejection fraction,EF)值将患者分为两组:EF≥50％,EF＜ 50％,将各多普勒超声心动图参数在各组对比分析.结果 随着心脏舒张功能障碍的进展,运用组织多普勒技术(TDI)测得的二尖瓣环舒张早期峰值速度(Ea)及其与舒张晚期峰值速度(Aa)的比值Ea/Aa降低(P＜0.01),其差别尤其表现在对照组与左室松弛性减低组及其与假性正常化组之间(P＜0.01).在正常对照组、冠心病心肌梗死EF正常组及冠心病心肌梗死EF减低组TDI测得的二尖瓣环收缩期峰值速度Sa、Ea及Ea/Aa比值呈逐渐降低趋势(P＜0.01).而且Spearman相关分析表明:Ea值及Ea/Aa比值与左室舒张功能障碍分级相关性良好,Sa与EF值相关性良好.结论 冠心病心肌梗死患者出现左室舒张功能障碍常先于左室收缩功能障碍,TDI测得的Ea及Ea/Aa比值可用于鉴别左室舒张功能的假性正常化;TD1测得的Sa可作为评估冠心病心肌梗死患者左室收缩功能的重要参数.     

Normalised radionuclide measures of left ventricular diastolic function

Abnormal left ventricular diastolic function is being increasingly recognised in patients with clinical heart failure and normal systolic function. A simple routine radionuclide measure of diastolic function would therefore be useful. To establish this, the relationship of peak diastolic filling rate (normalized for either end diastolic volume, stroke volume, or peak systolic emptying rate), and heart rate, age, and left ventricular ejection fraction was studied in 64 subjects with normal cardiovascular systems using routine gated heart pool studies. The peak filling rate, when normalized to end diastolic volume, correlated significantly with heart rate, age and left ventricular ejection fraction, whereas normalization to stroke volume correlated significantly to heart rate and age but not to left ventricular ejection fraction. Peak filling rate normalized for peak systolic emptying rate correlated with age only. Multiple regression equations were determined for each of the normalized peak filling rates in order to establish normal ranges for each parameter. When using peak filling rate normalized for end diastolic volume or stroke volume, appropriate allowance must be made for heart rate, age and ejection fraction. Peak filling rate normalized to peak ejection rate is a heart rate independent parameter which allows the performance of the patient's ventricle in diastole to be compared with its systolic function. It may be used in patients with normal systolic function to serially follow diastolic function or if age corrected, to screen for diastolic dysfunction.     

Normalised radionuclide measures of left ventricular diastolic function

Abnormal left ventricular diastolic function is being increasingly recognised in patients with clinical heart failure and normal systolic function. A simple routine radionuclide measure of diastolic function would therefore be useful. To establish this, the relationship of peak diastolic filling rate (normalized for either end diastolic volume, stroke volume, or peak systolic emptying rate), and heart rate, age, and left ventricular ejection fraction was studied in 64 subjects with normal cardiovascular systems using routine gated heart pool studies. The peak filling rate, when normalized to end diastolic volume, correlated significantly with heart rate, age and left ventricular ejection fraction, whereas normalization to stroke volume correlated significantly to heart rate and age but not to left ventricular ejection fraction. Peak filling rate normalized for peak systolic emptying rate correlated with age only. Multiple regression equations were determined for each of the normalized peak filling rates in order to establish normal ranges for each parameter. When using peak filling rate normalized for end diastolic volume or stroke volume, appropriate allowance must be made for heart rate, age and ejection fraction. Peak filling rate normalized to peak ejection rate is a heart rate independent parameter which allows the performance of the patient's ventricle in diastole to be compared with its systolic function. It may be used in patients with normal systolic function to serially follow diastolic function or if age corrected, to screen for diastolic dysfunction.     

射血分数保留的心力衰竭左心室舒张功能的影像学评价

射血分数保留的心力衰竭发病率在逐年上升。准确测量左室舒张功能有利于对该病的临床评价。目前可采用超声心动图、心脏MRI(CMRI)及其他多种检查方法评价左室舒张功能,并对舒张功能的病生理机制、舒张功能障碍分级有提示作用。其中CMRI技术的作用日益突出,包括舒张期容积-时间曲线、二尖瓣血流与肺静脉血流成像、心肌标记及其他CMRI技术。     

Myocardial scintigraphy, echocardiography and proBNP for early detection of myocardial cardiotoxicity in breast cancer patients after chemo-radiotherapy

The most severe side effect in breast cancer patients, treated with chemotherapy and/or radiotherapy is cardiotoxicity, leading to chronic heart failure and worsening the quality of life. The aim of our study was to detect early in these patients signs of cardiotoxicity. Twenty four breast cancer patients were included in our study after combined treatment (chemo and radiotherapy). We studied myocardial function by gated single photon emission tomography (GSPET-MS), echocardiography (EC) and 32 amino acid polypeptide B-type natriuretic peptide (ProBNP) measurements. We found early signs of cardiotoxicity in 10/24 investigated patients. All patients had no clinical symptoms, and normal electrocardiogram and left ventricular ejection fraction (LVEF). According to results from the performed tests, patients were divided in 4 groups: a) Normal systolic and diastolic LV function, normal ProBNP value, normal myocardial scintigraphy in 14/24 patients. b) Diastolic dysfunction, increased ProBNP value, hypoperfused defects in myocardial scintigraphy in 5/24 patients. c) Diastolic dysfunction, normal ProBNP value, hypoperfused defects in myocardial scintigraphy in 3/24 patients. d) Normal systolic and diastolic LV function, normal ProBNP value, hypoperfused defects in myocardial scintigraphy in 2/24 patients. In conclusion, in patients with breast cancer and asymptomatic cardiotoxicity, by applying GSPET-MS, ProBNP measurements and EC diastolic function tests, we detected early signs of myocardial damage in 10/24 patients 6-12 months after chemotherapy and radiotherapy.     

Diastolic dysfunction: Pathophysiology, clinical features, and assessment with radionuclide methods

Basic to our understanding of heart failure is the distinction between systolic and diastolic ventricular dysfunction. Diastolic dysfunction implies that the ventricle cannot accept blood at normally low pressures. The ventricular filling pattern and the relation between ventricular diastolic pressure and volume reflect a dynamic interaction between time course of relaxation, conversion of elastic forces into elastic recoil, and the passive properties of the ventricle. In the early part of diastolic filling, the pressure-volume relationship is influenced primarily by relaxation; in the latter part of diastole, passive filling properties are important. Mitral inflow patterns reflect these time-varying filling dynamics and are commonly assessed with echocardiography. Disorders of diastolic filling are observed in patients with heart failure with normal ejection fraction, myocardial ischemia, and even dilated cardiomyopathy. Patients with concentric ventricular hypertrophy, normal ejection fraction, and heart failure are the prototype of patients with diastolic dysfunction. In this article we review the physiology and pathophysiology of diastole and the main clinical disorders associated with diastolic dysfunction, and we outline in brief the application of radionuclide techniques in the assessment of diastolic dysfunction.     

超声心动图检查在评价乳腺癌化疗后左心功能中的价值研究

目的探讨超声心动图检查在评价乳腺癌化疗后左心功能中的价值。方法选取2019年7月至2021年6月在我院接受4个周期(T₁~T₄)以阿霉素为主化疗方案治疗的60例乳腺癌患者为研究对象,每个化疗周期后进行超声心动图检查,对比T₁~T₄后二维超声心动图参数[左心室收缩末期内径(LVDs)、左心室舒张末期内径(LVDd)、左心室射血分数(LVEF)、二尖瓣舒张早期最大血流速度/二尖瓣舒张晚期最大血流速度(E/A)、左心室后壁舒张末期厚度(LVPWT)、室间隔舒张末期厚度(IVST)]及左心房三维参数[左心房收缩末期容积(LAVmin)、左心房舒张末期容积(LAVmax)、左心房主动收缩前容积(LAVprep)]。结果化疗T₁~T₄后的LVDs、LVDd、LVEF、E/A、LVPWT、IVST相比,差异无统计学意义(P>0.05)。化疗T₂~T₄后的LAVmin、LAVmax、LAVprep均高于T₁后,差异有统计学意义(P<0.05)。结论实时三维超声心动图可早期发现乳腺癌化疗药物引发的左心功能变化,有助于为临床及时调整用药方案提供参考。     

Assessment of left ventricular diastolic function in patients receiving anthracycline therapy

Abnormalities in left ventricular filling have been described as an early finding in coronary artery disease and in cardiomyopathy. The present study was undertaken to determine whether impaired diastolic function may be an early sign of anthracycline cardiotoxicity. Radionuclide left ventricular curves of 30 treated patients were compared with the curves of 17 normal, agematched, volunteers. The curves were analyzed for ejection fraction, peak filling rate (normalized for end diastolic counts and for stroke counts), time to peak filling rate and filling fraction in the first third of diastole normalized for cycle length. In 20 patients (Groups A and B), we analyzed the radionuclide ventriculography preceding the decrease of systolic function or a clinical congestive heart failure. In ten patients (Group C) who ended a treatment regimen without systolic dysfunction or clinically evident cardiotoxicity, we analyzed the ventriculography at the end of the therapy. Among the diastolic indexes, only the first third filling fraction was abnormal in a minority of the patients (6/20 in Groups A and B). Our findings suggest that diastolic dysfunction is uncommon in anthracycline treated patients prior to systolic dysfunction.     

Left ventricular systolic and diastolic dyssynchrony assessed by phase analysis of gated SPECT myocardial perfusion imaging: a comparison with speckle tracking echocardiography

Objective

The objective of this study was to compare left ventricular (LV) systolic and diastolic dyssynchrony parameters measured by phase analysis on gated single-photon emission computed tomography (SPECT) myocardial perfusion imaging (MPI) with those measured by speckle tracking echocardiography (STE).

Materials and methods

Two patient groups were enrolled from the Chang Bing Show Chwan Memorial Hospital. The systolic group consisted of patients with reduced LV ejection fraction (LVEF) of <50 % as assessed by routine echocardiography. The diastolic group consisted of patients with normal LVEF (>50 %) and diastolic dysfunction according to routine echocardiography (E/A <1, E/E′ >8). LV systolic and diastolic dyssynchrony parameters were calculated using STE as the maximal peak-time delay between peak radial strains of two opposing LV walls and as the standard deviation of the time to peak radial strains in 6 mid-LV segments. All of the patients had gated SPECT MPI within 6 ± 11 days post STE. Phase analysis was performed on the resting gated SPECT MPI images to calculate systolic and diastolic phase standard deviation and phase histogram bandwidth as markers of LV systolic and diastolic dyssynchrony, respectively.

Results

Fifty-two consecutive patients (40 men, mean age = 66 ± 13 years, LVEF = 34.4 ± 10.2 %) were enrolled in the systolic group, whereas 30 consecutive patients (15 men, mean age = 69 ± 11 years, LVEF = 72.3 ± 4.7 %, E/A all <1, E/E′ = 11.7 ± 2.2) were enrolled in the diastolic group. LV systolic and diastolic dyssynchrony parameters measured by phase analysis of gated SPECT MPI and STE were correlated well in both systolic and diastolic groups, respectively.

Conclusion

Phase analysis on gated SPECT MPI showed good correlations with STE and is suitable for the assessment of LV systolic and diastolic dyssynchrony. As assessed with the phase analysis and STE techniques, the patients with severe LV systolic dysfunction had severe LV systolic dyssynchrony, but the patients with LV diastolic dysfunction were not necessarily with LV diastolic dyssynchrony, indicating that the LV diastolic dyssynchrony parameters characterized independent mechanisms of LV regional diastolic function.     

Left ventricular diastolic function assessment from three-dimensional three-directional velocity-encoded MRI with retrospective valve tracking

Purpose

To compare parameters describing left ventricular (LV) diastolic function obtained with three‐dimensional (3D) three‐directional velocity‐encoded (VE) MRI with retrospective valve tracking and two‐dimensional (2D) one‐directional VE MRI in patients with ischemic heart failure. Second, to compare classification of LV diastolic function, and in particular for discriminating restrictive filling patterns, with both MRI techniques versus Doppler echocardiography.

Materials and Methods

The 3D and 2D VE MRI early (E) and atrial (A) peak flow rate indices, determined from transmitral waveform analyses, were compared. Also, net forward flow volume per cycle and transmitral regurgitation fraction were determined. Agreement in classifying diastolic filling patterns between 3D and 2D VE MRI versus Doppler echocardiography was evaluated using kappa statistics.

Results

The 3D three‐directional VE MRI with retrospective valve tracking was statistically significantly different from 2D one‐directional VE MRI for net forward flow volume and regurgitation fraction through the mitral valve and all parameters describing the diastolic waveform filling pattern, except for the E deceleration time and E/A filling ratio. Kappa‐agreement between 3D three‐directional VE MRI with retrospective valve tracking and echocardiography for classifying diastolic filling patterns was superior to 2D one‐directional VE MRI and echocardiography (i.e., κ = 0.91 versus κ = 0.79, respectively).

Conclusion

The 3D three‐directional VE MRI with retrospective valve tracking better describes LV diastolic function as compared to 2D one‐directional VE MRI in patients with ischemic heart failure. J. Magn. Reson. Imaging 2011;33:312–319. © 2011 Wiley‐Liss, Inc.     

Evaluation of normal erectile function with color flow Doppler sonography

To understand better the vascular events that occur during normal erection, we used color flow Doppler sonography to examine the erectile process in seven normal subjects. The relationship of systolic/diastolic velocities and spectral waveform changes in the penile arteries was studied in response to increasing pressure within the corpora cavernosa (tumescence) before and after the intracorporal administration of drugs to induce erection. A characteristic spectral waveform pattern was identified throughout the erectile cycle, and the pattern was correlated with increasing pressure. Both systolic and diastolic velocities were elevated during the initiation of erection, at which time the pressure within the corpora cavernosa was low (11-25 mm Hg). Systolic velocities remained elevated until the last phase of erection (83-106 mm Hg). Diastolic velocity decreased as the intracorporal pressure increased from 25 to 40 mm Hg. Between 40 and 63 mm Hg, diastolic velocity approximated zero. With increasing pressure (63-83 mm Hg), diastolic flow reversed. As the corpora cavernosa approached full erection (83-105 mm Hg), both the forward systolic and reverse diastolic flow components diminished. At approximately 106 mm Hg (systolic occlusion pressure), flow ceased. Systolic/diastolic velocity and waveform phase relationships could be used to define the integrity of both the cavernosal artery inflow and the venous sinusoidal outflow occlusion mechanisms. Color flow Doppler sonography enhanced our ability to observe and quantify dynamic erectile events and provided new insights into understanding normal erectile function.     

Assessment of normal and abnormal erectile function: color Doppler flow sonography versus conventional techniques

The penile arteries were studied with color Doppler flow sonography in 10 subjects with normal and 39 patients with abnormal erectile function. The relationships of systolic and diastolic velocities to spectral waveform changes in the penile arteries in response to tumescence were studied before and after intracorporal injection of vasoactive medications that induce erection. In normal subjects, a characteristic spectral waveform pattern corresponded to increasing intracorporal pressure. Patients with abnormal arterial inflow and/or abnormal venous sinusoidal leakage demonstrated deviation from the patterns noted in normal subjects. Patients with abnormal arterial inflow had lower mean peak systolic velocities than normal subjects. Patients with severe venous sinusoidal incompetence had an arrest of waveform progression with evolution to but not beyond phases 1 or 2 (diastolic flow remained positive). Patients with abnormal arterial inflow and abnormal venous sinusoidal outflow had waveform changes that reflected both processes. Systolic/diastolic velocity and waveform relationships can be used to define the integrity of both the cavernosal artery inflow and venous sinusoidal outflow occlusion mechanisms.