Relations between resting ventricular long axis function, the electrocardiogram, and myocardial perfusion imaging in syndrome X

Longitudinal myocardial function is more compromised in cardiac syndrome X compared to insignificant CAD: Role of stress echocardiography and calcium scoring

BACKGROUND AND AIM

The aim of this study was to assess the nature of myocardial dysfunction in the cardiac syndrome X (CSX) and insignificant coronary artery disease (ICAD) using dobutamine stress echocardiography (DSE) and coronary calcium scoring (CAC).

METHODS

We prospectively studied 35 consecutive patients who complained of exertional angina, had ≥1 mm ST shift on exercise stress test but normal or no obstructive CAD (<50%) on angiography. Patients were divided into CSX (n = 27) with normal arteries and ICAD (n = 8) with insignificant stenosis.

RESULTS

CSX patients had more females, lower calcium score and less prevalent cardiac risk factors compared to ICAD (p < 0.05 for all). At peak stress, MAPSE and TAPSE failed to increase in both groups. LV septal and lateral s' increased in the two groups but the increment increase was less in CSX than ICAD (p < 0.05) while other diastolic indices did not differ between groups (p > 0.05 for all). CAC correlated modestly with LV and RV systolic velocities: septal s' (r = -0.65, p < 0.001) lateral s' (r = -0.35, p = 0.04) and right s' (r = -0.53, p = 0.005) in CSX, while in ICAD patients only with RV s' (r = -0.58, p = 0.02). On multivariate model, only septal s' OR 1.816 (1.1090-3.820, p = 0.04) proved the most powerful independent predictor of CAC.

CONCLUSIONS

Compromised LV longitudinal systolic velocities were more pronounced and calcium score as a surrogate for atherosclerosis was lower in CSX than ICAD. These findings strengthen the evidence for different pathogenesis of CSX compared to ICAD, with microvascular disease in the former and calcification in the latter.

Reduced regional strain rate is the most accurate dysfunction in predicting culprit lesions in patients with acute coronary syndrome

BACKGROUND AND AIM

Predicting culprit lesions in acute coronary syndrome (ACS) could be a challenge. The aim of this study was to assess the accuracy of regional wall motion abnormalities (RWMA) using various echocardiographic techniques and ECG changes in predicting the culprit coronary lesion in a group of patients with ACS.

METHODS

In 80 consecutive patients with ACS (age 55·7 ± 9·4 years, 77% male, 15% with CCS Angina III), an echocardiographic examination of left ventricle (LV) RWMA, tissue Doppler imaging (TDI) and speckle tracking myocardial strain and strain rate (SR) were performed before intervention.

RESULTS

Of the 80 patients, one-vessel stenosis (>70%) was present in 53 (66%), two-vessel disease in 12 (15%) and multivessel disease in 15 patients (19%). About 51% of patients had hypertension, 40% diabetes and 23% dyslipidaemia. There was no relationship between individual segmental RWMA and SR. Mean regional SR, but not peak strain, correlated with culprit lesion branch: left anterior descending - LAD (r = 0·35, P = 0·005), circumflex LCx (r = 0·32, P = 0·03) and right coronary RCA (r = 0·37, P = 0·01). Only ECG changes in the LAD territory (r = 0·26, P = 0·04) correlated with the culprit lesion. SR of LAD territories ≤-0·74 was 71% sensitive and 70% specific (AUC = 0·70, CI = 0·67-0·93, P = 0·01), SR of LCx territories of ≤-0·67 was 75% sensitive and 63% specific (AUC = 0·72, CI = 0·58-0·87, P = 0·02) and SR of RCA territories ≤-0·83 was 73% sensitive and 71% specific (AUC = 0·80, CI = 0·66-0·93, P = 0·001) in predicting significant stenosis. SR was more accurate than all other techniques in predicting the culprit lesion.

CONCLUSION

In ACS, mean regional speckle tracking SR is more sensitive than peak strain, TDI, ECG changes and wall motion abnormalities in detecting significant coronary artery stenosis.

Effects of neuropeptide Y on coronary artery vasomotion in patients with microvascular angina

BACKGROUND

Patients with microvascular angina (exertional angina, positive exercise tests and normal coronary arteriograms) usually have a reduced coronary blood flow reserve. Neuropeptide Y (NPY) is a potent endogenous vasoconstrictor involved in modulation of coronary vasomotor tone and may play a role in microvascular angina.

METHODS

We compared the effects of NPY (0.2-1.0pmol/kg, intracoronary) on the vasomotor response of proximal and distal segments of the coronary arteries in 7 patients with microvascular angina, 9 with chronic stable angina, and 9 control individuals. The coronary response to the administration of ergonovine was also assessed in 9 other patients with microvascular angina. Computerized coronary artery diameter measurements were carried out before (baseline) and after the administration of the vasoactive agents.

RESULTS

Mean baseline coronary lumen diameters were similar in control, microvascular angina, and coronary artery disease patients. NPY constricted proximal coronary segments by 8±2%, 5±2% and 6±3% and distal segments by 14±2%, 11±2% and 10±2% in control, microvascular angina, and coronary artery disease patients, respectively (p=NS between groups). In patients with microvascular angina, ergonovine constricted proximal coronary segments by 7±1.5% and distal segments by 12.5±3% (p=NS vs. NPY). During NPY administration four microvascular angina patients developed chest pain, ST segment depression, and a marked lengthening of the contrast medium run off, in the absence of epicardial coronary artery spasm. Control individuals and coronary artery disease patients did not experience chest pain, ST segment shifts, or lengthening of the run off during NPY administration. Ergonovine administration caused chest pain and lengthening of the contrast run-off, in the absence of epicardial coronary artery spasm, in one microvascular angina patient.

CONCLUSIONS

Exogenous NPY causes mild epicardial coronary artery constriction which is similar in patients with non-cardiac chest pain, microvascular angina and coronary artery disease. Myocardial ischemia and marked lengthening of the contrast run off in response to NPY occurred in microvascular angina patients but not in control or coronary artery disease patients. An abnormal constrictor response to NPY at the microcirculation level could be the mechanism underlying the ischemic manifestations observed in patients with microvascular angina.

CONDENSED ABSTRACT (TABLE OF CONTENTS)

The vasomotor response of proximal and distal coronary artery segments was studied in twenty five patients: 7 microvascular angina, 9 chronic stable angina, and 9 control subjects. Computerized measurements of coronary diameters were carried out before and after the intracoronary administration of neuropeptide Y (NPY) and ergonovine. Constriction of epicardial arteries in response to NPY was mild and not significantly different in control, microvascular angina and coronary artery disease patients. Ergonovine-induced epicardial coronary artery constriction was similar to that of NPY. However, NPY caused transient myocardial ischemia in patients with microvascular angina (probably through constriction of the small intramyocardial vessels), but not in control subjects or coronary artery disease patients.

Coronary calcification with no flow limiting lesions: A potential cause for ischaemic dysfunction in syndrome X patients

Aim

Exertional angina in patients with no coronary flow limiting lesions remains a clinical puzzle. We aimed to assess the extent of coronary artery calcification (CAC) and its relationship to ventricular wall motion function using stress echocardiography in a group of patients limited by exertional angina, but no obstructive lesions.

Methods

We compared CT coronary calcium score (CACS) and dobutamine stress echocardiography in 55 patients (age 64.7 ± 7.7 years), divided into Group 1 (CACS ≤ 100) and Group 2 (CACS > 100). No patient had LV ejection fraction-EF < 55%, pulmonary hypertension, arrhythmia, renal failure or parathyroid disease. Multiple linear regression analysis was used to test the association between gender-standardized continuous echocardiographic parameters and patient groups adjusted for age, body surface area, osteoporosis and CV risk factors and CACS.

Results

At rest, LV long axis ‘subendocardial’ function was reduced (amplitude: β − 1.11 SD, p < 0.05, R² 0.6 and systolic velocity: β − 1.08 SD, p < 0.05, R² 0.44), left atrial (LA) indexed volume was raised (β 1.06 SD, p < 0.05, R² 0.37) and its systolic velocity decreased (β − 1.05 SD, p < 0.05, R² 0.35) in Group 2. With stress, wall motion score index increased (p < 0.05) and long axis disturbances worsened only in the same group. Multivariate analysis demonstrated clear relationship between ischaemic LV disturbances, reduced long axis amplitude, global longitudinal systolic strain and early diastolic strain rate. Resting and stress RV lengthening velocity also correlated with CAC score.

Conclusion

In symptomatic patients with no obstructive coronary lesions and with more than mild CAC, long axis disturbances and wall motion score index rise occur with stress, at the time of symptom development and correlate with severity of arterial calcification. These findings suggest CAC as a potential mechanism for coronary wall stiffness and consequently exertional ischaemic changes as a result of limited flow reserve.

Relationship Between Systolic Pulsed Wave Tissue Doppler Parameters and Both Invasive and Noninvasive Reperfusion Criteria in Patients with Acute Anterior Myocardial Infarction Undergoing Primary Percutaneous Coronary Intervention

BACKGROUND

Despite normal flow in the infarct-related artery after primary percutaneous coronary intervention, patients may not achieve adequate perfusion at the tissue level. We examined the applicability of pulsed wave tissue Doppler (PTD) in detection of successful myocardial reperfusion.

METHODS

In all, 24 patients with anterior infarction were enrolled. All patients underwent primary percutaneous coronary intervention. PTD was performed 2 days and 2 weeks after percutaneous coronary intervention, and recorded from 6 different locations at the mitral annular level. Peak systolic wave was determined and was related to various markers of reperfusion.

RESULTS

Systolic PTD measurement in patients with myocardial blush grades 0 to 1 significantly deteriorated between second day and second week (6.5 +/- 1.1-5.3 +/- 1.1 for the anterior wall, and 6.2 +/- 1.3-5.3 +/- 1 for the anterior septum, P < .05 and P < .01, respectively). Systolic PTD parameters improved significantly in patients with myocardial blush grades 2 to 3 (6 +/- 1.5-7.2 +/- 2 for the anterior wall, and 5.4 +/- 1.1-7.1 +/- 1.6 for the anterior septum, P < .05 and P < .01, respectively). A significant relationship was observed between PTD and thrombolysis in myocardial infarction flow, S-T resolution, and creatine phosphokinase peaking. PTD recovery was highly sensitive and specific for the detection of left ventricular function recovery.

CONCLUSION

We demonstrated a significant relationship between systolic PTD parameters and invasive and noninvasive markers of reperfusion. Larger studies are needed to confirm these results.

Clinical applications of strain rate imaging

Myocardial strain (epsilon) is a dimensionless index of change in myocardial length in response to an applied force. epsilon Rate (SR) is the rate of change of length and is usually obtained as the time derivative of the epsilon signal. In echocardiography, SR is calculated as the difference between 2 velocities normalized to the distance between the 2 velocities. SR imaging (SRI) has a theoretic advantage over Doppler tissue imaging in that SRI is relatively immune to cardiac translational motion and tethering. Therefore, SRI may be superior to Doppler tissue imaging in quantitative assessment of regional myocardial function and may find clinical application in the interrogation of coronary artery disease. The high frame rates of SRI have also renewed interest in timings of global and regional mechanical events, and their potential clinical applications. The high temporal resolution allows SRI to depict regional systolic and diastolic asynchrony. Ongoing clinical trials will determine the sensitivity, specificity, and accuracy of SRI parameters for a variety of clinical conditions. Potential clinical applications include investigation of ischemia (at rest and with stress), myocardial viability, and altered global and regional systolic and diastolic function in cardiomyopathies. Suboptimal signal quality remains a major limitation of strain imaging, and advances in data acquisition and postprocessing capabilities will help determine its future incorporation into standard regional myocardial assessment.

Second-generation tissue Doppler with angle-corrected color-coded wall displacement for quantitative assessment of regional left ventricular function

To test the hypothesis that a new tissue Doppler (TD) approach using angle-correction and transformation of velocity data to color-coded displacement data may objectively quantify regional left ventricular function, in vitro experiments were first performed with an oscillating echo target precisely controlled by a microstepping motor. Displacement varied from 1 to 15 mm (60 to 130 cycles/min) at angles of 0 degrees and 45 degrees to the echo transducer. Custom software transformed TD data to displacement data. Sixty-five subjects were then studied: 35 with wall motion abnormalities and 30 normal controls. Results were compared with independent visual assessment and caliper measurements of endocardial excursion from gray-scale images. In vitro displacement imaging strongly correlated with true displacement (r = 0.99, p <0.0001). In humans, peak transmural displacement discriminated normal results (6.3 +/- 3.2 mm) from hypokinesia (2.7 +/- 1.8 mm, p <0.05), akinesia (0.4 +/- 1.2 mm, p <0.05) from hypokinesia, and dyskinesia (-1.9 +/- 1.2 mm, p <0.05) from akinesia. Normal subendocardial displacement was 5.9 +/- 2.9 versus 4.0 +/- 3.9 mm in the epicardial layer (p <0.01). This displacement gradient was absent in abnormal segments. Displacement data correlated with endocardial excursion by calipers (parasternal views: r = 0.86, all views: r = 0.79, both p <0.0001). Overall accuracy of displacement imaging was 82% (kappa = 0.71) versus 66% (kappa = 0.43) for visual assessment with caliper data as the standard of reference. Angle-corrected displacement imaging was superior to routine visual assessment and is a promising new method to quantify regional left ventricular function.

Left septal fascicular block: myth or reality?

Anatomic studies have shown that the left bundle branch divides into three fascicles in most humans. Changes in the 12 lead ECG (electrocardiogram) due to conduction abnormalities of the left anterior fascicle and left posterior fascicle are now part of the standard repertoire of electrocardiographic interpretation. There are no standard criteria for detecting conduction defects involving the third left fascicle, the septal or median fascicle, and the very existence of such defects is still a matter of controversy. The purposes of this article are to review the available evidence on this subject, suggest electrocardiographic criteria for its recognition, and present examples which illustrate that left septal fascicular block does indeed exist as a specific entity. Left septal fascicular block is a polymorphic conduction defect which may explain some previously inadequately understood electrocardiographic abnormalities.

Relationship between noninvasive reperfusion criteria and pulsed-wave tissue Doppler parameters in patients with acute myocardial infarction receiving thrombolytic therapy

Several studies have proven that noninvasive reperfusion criteria (NRC) have prognostic significance in patients receiving thrombolytic therapy (TT) after acute myocardial infarction (acute MI). In this study, we investigated the relationship between NRC and pulsed tissue Doppler (PTD) parameters in patients receiving TT after acute MI, and the role of PTD in the management and follow-up of patients with acute MI. The study group(n= 41)was divided into four subgroups defined as: anterior and posterior MI, with or without NRC. In the first PTD measurements (2-3 days after acute MI), all acute MI patients had significantly smaller peak systolic (S-wave) velocity in all evaluated segments and longer Q-Speak durations (time elapsed from the inscription of the Q-wave on the surface ECG to the peak of the S-wave in PTD) as compared with control patients(n= 22; P < 0.001 for both). Among the diastolic parameters, the E/A ratio was significantly smaller in the study group compared with the control group(P < 0.001). Among the patients who had received TT in the first 2 hours, those patients who had NRC displayed significantly higher peak S-wave values in all evaluated segments than those without NRC(P < 0.05). The second PTD study (4-5 weeks after acute MI), revealed that the difference between the systolic PTD parameters of the noninfarcted regions of the study and control groups disappeared. Infarct-related segments, however, displayed significant improvement only in patients having NRC. There was a significant positive correlation between the mean mitral annular S-wave velocity and left ventricular ejection fraction(r = 0.59, P < 0.001). In conclusion, a significant relationship was observed between the PTD parameters and the NRC, which are known to have prognostic significance.

Diastolic response during dobutamine stress echocardiography evaluated by a tissue velocity imaging technique is a sensitive indicator for diagnosing coronary artery disease

BACKGROUND

Tissue velocity imaging (TVI) is a new method that measures regional myocardial velocities on the basis of color Doppler myocardial imaging principles.

METHODS

To diagnose coronary artery disease (CAD) objectively by evaluating left ventricular diastolic responses during dobutamine stress echocardiography (DSE) with TVI, we performed DSE in 22 healthy participants and 28 patients with angina pectoris without wall-motion abnormality at rest. Before and during DSE, we measured the differences of time intervals from the R wave on electrocardiogram to the peak of early diastolic myocardial velocity in the same cardiac cycle between basal segments and midsegments in the septal (dT-S) and inferior (dT-I) walls by TVI.

RESULTS

During DSE, dT-S in patients with left anterior descending CAD and dT-I in patients with right CAD were prolonged compared with that in healthy participants (both P <.01). The localization of the segments with a dT-S or dT-I during low-dose (10 microg/kg/min) dobutamine infusion of >32 milliseconds allowed the correct identification of the stenosed vessel in 87% of 23 patients for whom DSE was performed with the TVI technique before coronary angiography.

CONCLUSIONS

The analysis of regional left ventricular diastolic responses to dobutamine stress using TVI was useful for the objective diagnosis of CAD.

Apical tissue tracking echocardiography for characterization of regional left ventricular function: comparison with magnetic resonance imaging in patients after myocardial infarction

OBJECTIVE

The purpose of this study was to characterize the normal pattern of apical tracking and to investigate whether tissue tracking imaging is more useful for evaluation of regional left-ventricular function than noncontrast harmonic echocardiography in patients after myocardial infarction.

BACKGROUND

Left ventricular longitudinal shortening plays an important role in cardiac contraction, and can be evaluated online by a new Doppler tissue imaging method.

METHODS

We included 40 healthy participants and 40 patients after myocardial infarction. They underwent tissue tracking imaging and noncontrast harmonic imaging by an experienced and an inexperienced observer. Diagnostic accuracy of semiquantitative evaluation of left ventricular function was compared using magnetic resonance imaging as reference method.

RESULTS

Velocity-time integrals decreased from basal to apical segments in healthy participants. Tissue tracking imaging has a higher diagnostic sensitivity than noncontrast imaging for the diagnosis of regional wall-motion abnormalities (expert, 78% vs 97%, P <.01; beginner, 63% vs 91%, P <.001), whereas specificity remained unchanged (expert, 99% vs 97%, not significant; beginner, 91% vs 92%, not significant).

CONCLUSIONS

Tissue tracking imaging is feasible and evaluates regional systolic myocardial function quantitatively with high diagnostic accuracy compared with magnetic resonance imaging in patients after myocardial infarction, and is more accurate than noncontrast harmonic echocardiography.

Strain and strain rate echocardiography

Strain and strain rate echocardiography is an emerging technique for assessing myocardial systolic and diastolic function. It is envisioned that this modality could change the quantitative assessment of regional wall motion and improve the accuracy and reproducibility of test readings. Myocardial strain and strain rate can detect inducible ischemia and at earlier stages than visual estimation of wall motion or wall thickening parameters. Changes in systolic strain rate and strain have potential to discriminate between different myocardial viability states. Measurement of diastolic rate of deformation can differentiate physiologic from pathologic hypertrophy, and restrictive from constrictive cardiomyopathy. This article reviews basic principles and current experimental and clinical applications of strain and strain rate echocardiography.

Adenosine provokes diastolic dysfunction in microvascular angina

Adenosine stress echocardiography was performed in nine patients (58 (+/-3) years, eight women) with documented microvascular angina. Global ventricular function was assessed by Tc(99m) blood pool imaging and Doppler, whereas longitudinal ventricular function was assessed by simultaneous tissue Doppler echocardiography of the lateral mitral annulus. Adenosine was infused incrementally to onset of chest pain in all patients. There was no significant change in global or longitudinal systolic function. Adenosine induced global diastolic dysfunction, demonstrated by blood pool imaging and by Doppler of the transmitral flow. All patients had long axis diastolic dysfunction at peak adenosine, revealed by a ratio of early to late diastolic velocity of lateral mitral annulus <1, which was absent at rest. Adenosine, as a stress agent, provokes regional and global diastolic dysfunction in microvascular angina, which may be a consequence of subendocardial ischaemia. Long axis diastolic dysfunction can be easily revealed by tissue Doppler of the lateral annular motion.

Absent septal Q waves in otherwise normal electrocardiograms--a variant of normal?

Absence of septal Q waves can be defined as the simultaneous absence of Q waves from all of leads I, V(5), and V(6). This has been considered abnormal by some investigators, but whether this is true of tracings lacking other abnormalities is uncertain. In electrocardiograms (ECGs) from 4,174 patients, 95 were found that were normal except for absence of septal Q waves. Clinical characteristics of these were compared to those of age- and gender-matched patients having normal ECGs with septal Q waves. The ratio of the number of patients with normal ECGs except for absent septal Q waves to the number of patients with entirely normal ECGs was independent of age. Most patients having normal ECGs except for absent septal Q waves had clinically normal hearts, and they were not significantly more likely to have apparent cardiovascular disease than age- and gender-matched controls with septal Q waves. It is concluded that absence of septal Q waves in otherwise normal ECGs may be a variant of normal.

Regional asynchrony during acute myocardial ischemia quantified by ultrasound strain rate imaging

OBJECTIVES

We propose a new method to easily quantify asynchronous wall motion due to postsystolic shortening (PSS). We also studied the relationship of the spatial and temporal extent of PSS to the extent of myocardium at ischemic risk after variable duration of ischemia.

BACKGROUND

Postsystolic shortening is a sensitive marker of asynchrony during ischemia. Current techniques for detection of asynchrony are either subjective, or invasive and time-consuming. Strain rate imaging (SRI) can noninvasively depict PSS as prolonged compression/expansion crossover.

METHODS

Nineteen open-chest pigs were scanned from apical views, before and after left anterior descending coronary artery occlusion. Strain rates were derived offline from tissue Doppler velocity cineloops. The time from electrocardiographic R-wave to the occurrence of compression/expansion crossover (TCEC) was calculated. Prolonged TCEC during ischemia was identified using a standardized analysis and both spatial (% of left ventricle) and temporal extent were quantified. The extent of myocardium at risk was measured in seven animals from dye-stained specimens.

RESULTS

Prolonged TCEC was found in all ischemic segments. There was a good correlation (r = 0.91; p < 0.001) and good agreement between the spatial distributions of prolonged TCEC and myocardium at risk. The extent of myocardium at risk was better approximated by TCEC measurement (36 +/- 7% vs. 39 +/- 8%, respectively; p = NS) than by wall motion analysis (47 +/- 17%, p < 0.05). The duration of occlusion did not prolong TCEC.

CONCLUSIONS

Prolonged TCEC consistently occurs in ischemic myocardium and is apparently not affected by the duration of ischemia. Standardized analysis of TCEC in SRI closely quantifies the extent of ischemic myocardium. This new method may be a useful tool in other cardiac conditions associated with regional diastolic asynchrony.

Myocardial longitudinal motion by tissue velocity imaging in the evaluation of patients with myocardial infarction

Left ventricular (LV) longitudinal shortening plays an important role in cardiac contraction and is invariably affected by the presence of coronary artery disease. Third-generation tissue velocity imaging (TVI) color-maps cardiac movement by obtaining mean velocities of LV segments from the same set of beats. The goals of this study were to characterize patterns of longitudinal myocardial motion velocity in healthy subjects and to use these patterns to evaluate abnormal segments of patients with myocardial infarction (MI). Included were 20 healthy subjects and 16 patients with MI who underwent a 2-dimensional Doppler echocardiography study. Myocardial velocity profiles were taken at the anulus, basal, mid, and apical segments of the septal and lateral walls in the apical view. Segmental velocity patterns from healthy subjects were compared with abnormal segments in patients with MI. Both lateral and septal walls of healthy subjects showed significant basal-apical myocardial velocity reductions in systolic shortening (Sm) and early and late diastolic lengthening (Em and Am) and a basal-apical increase in the Em/Am ratio. The lateral wall had greater Sm and Em velocities than the septal wall. The Sm and Em velocities and the Em/Am ratio were significantly reduced in the abnormal segments in patients with MI. Latent lateral wall ischemia may have been detected in 5 of 9 patients with septal infarction, showing reduced Sm velocity in apparently normal lateral walls. In conclusion, TVI objectively quantifies directional and incremental changes in myocardial movement that are useful in evaluating global and regional myocardial function, and it may play a role in the detection of early myocardial ischemia.

Amplitudes, durations, and timings of apically directed left ventricular myocardial velocities: I. Their normal pattern and coupling to ventricular filling and ejection

BACKGROUND

The left ventricular (LV) major axis shortening is an important determinant of its global function. But unlike the LV minor axis dynamics, the long-axis dynamics have not been well characterized. We investigated the amplitudes, durations, and timings of LV long-axis myocardial velocities and related them to LV filling and ejection in normal healthy volunteers.

METHODS AND RESULTS

Myocardial velocities from the basal, mid, and distal portions of the four LV walls were recorded from the apical window with spectral Doppler tissue imaging in 20 normal individuals. The timings, amplitudes, and durations were measured and compared both longitudinally and circumferentially. These were also related to mitral inflow and LV ejection. Analysis of the recordings indicated that there were three principal myocardial velocities: apically directed systolic velocity and atrially directed early and late diastolic velocities. The LV posterior wall had the highest shortening velocity and the amount of shortening. The lateral wall had the greatest amplitude of early diastolic lengthening velocity, amount of lengthening, and early to late lengthening velocity and integral ratios, probably indicating most favorable early diastolic properties. There was a striking synchrony in the myocardial velocities circumferentially. The myocardial velocities dropped progressively as the sampling site was moved distally and the LV apex was practically stationary. Although the onsets of the velocity profiles were simultaneous in the meridional orientation, their durations were shorter distally. All myocardial velocities preceded the corresponding blood flow velocities. They also ended before the corresponding blood flow velocities, this being more pronounced in the distal myocardial segments, indicating the presence of inertial factors responsible for the terminal portions of mitral and aortic flows.

CONCLUSIONS

Recording of apically directed myocardial velocities gives valuable insights into the regional myocardial function. These velocities show significant regional variations in healthy normal individuals. It is speculated that analysis of regional myocardial velocities may have a role in the diagnosis of early myocardial disease.

Amplitudes, durations, and timings of apically directed left ventricular myocardial velocities: II. Systolic and diastolic asynchrony in patients with left ventricular hypertrophy

BACKGROUND

Regional myocardial dysfunction may be the earliest manifestation of myocardial disease and can occur in the absence of abnormalities of global left ventricular (LV) function. The LV long-axis function, which is mainly due to subendocardial muscle fibers, may become abnormal in the presence of normal short-axis function. This study investigates the temporal and spatial characteristics of the LV long-axis function in patients with secondary LV hypertrophy in the presence of normal systolic function.

METHODS AND RESULTS

LV long-axis myocardial velocities were recorded in 18 patients with LV hypertrophy and preserved regional and global systolic function with Doppler tissue imaging. Apically directed myocardial velocities were recorded from the basal, mid, and apical segments of the four LV walls, and their amplitudes, timings, and durations were measured. The abnormalities uncovered by the analysis of regional myocardial velocities included (1) asynchrony in the onset of myocardial contraction circumferentially, (2) presence of postejection LV shortening, (3) asynchrony in the onset of early myocardial lengthening circumferentially, (4) reduced early myocardial lengthening velocity, (5) reduced early to late myocardial lengthening velocity and extents circumferentially, and (6) lack of variation in the basal myocardial velocities circumferentially in contrast to normal individuals.

CONCLUSIONS

Patients with secondary LV hypertrophy with preserved regional and global systolic performance have distinct abnormalities in the timings and amplitudes of apically directed myocardial velocities. These abnormalities may explain some of the changes in LV global diastolic behavior and may also serve as markers of early regional myocardial dysfunction.

17-beta-Estradiol therapy lessens angina in postmenopausal women with syndrome X

OBJECTIVES

We sought to investigate the hypothesis that estrogen replacement therapy ameliorates symptoms in postmenopausal women with syndrome X.

BACKGROUND

Syndrome X (angina pectoris, positive findings on exercise electrocardiography and normal results on coronary angiography) frequently occurs in menopausal women. This observation, in conjunction with the known vasoactive properties of estrogens, suggests that estrogen depletion may contribute to the pathogenesis of syndrome X in some women.

METHODS

Twenty-five postmenopausal patients with syndrome X completed a double-blind, placebo-controlled study of the effect of 17-beta-estradiol cutaneous patches (100 micrograms/24 h) on the frequency of chest pain and on exercise tolerance. Patients were randomly assigned to receive either placebo or 17-beta-estradiol patches for 8 weeks and were then crossed over to the other treatment.

RESULTS

During the placebo phase, patients had a mean of 7.3 episodes of chest pain/10 days. A reduction to 3.7 episodes/10 days was observed during the 17-beta-estradiol phase (p < 0.05). No significant differences were observed between the effects of 17-beta-estradiol and placebo on exercise duration or the results of other cardiologic investigations.

CONCLUSIONS

Estrogen replacement reduces the frequency of chest pain and may be a useful new therapeutic option for treating postmenopausal women with syndrome X.

Absent septal q wave on electrocardiogram: a forgotten marker of myocardial disease

Though absence of the septal q wave on a standard ECG was recognised by Willem Einthoven, this abnormality has received little attention. Nevertheless it is common in patients with coronary artery disease, and strongly associated with fibrosis of the septum with or without infarction. Furthermore, the associated disturbance of ventricular activation has clear mechanical consequences, impairing both systolic and diastolic left ventricular performance. Its structural, functional, and possible prognostic significance combined with ease of its detection all suggest that the cardiographic sign of absence of the septal q wave should be more widely recognised as a noninvasive marker of ventricular disease.