Characteristics and clinical implications of premature summation of early and late diastolic filling in patients without tachycardia

Backgrounds

The summation of early (E) and late diastolic filling (A) on mitral inflow Doppler even in the absence of tachycardia is often found during assessments of left ventricular (LV) diastolic function. We evaluated the echocardiographic characteristics and clinical implications of premature E-A summation.

Methods

We identified 1,014 subjects who showed E-A summation and normal LV ejection fraction between January 2019 and June 2021 in two tertiary hospitals. Among these, 105 (10.4%) subjects showed premature E-A summation at heart rates less than 100 beats per minute (bpm). The conventional echocardiographic parameters and LV global longitudinal strain (GLS) were compared with 1:1 age, sex, and heart rate matched controls without E-A summation.

Results

The premature E-A summation group had a heart rate of 96.4±3.7 bpm. Only 4 (3.8%) subjects were classified as having LV diastolic dysfunction according to the current guidelines. That group showed prolonged isovolumic relaxation time (107.2±25.3 vs. 61.6±15.6 msec, p<0.001), increased Tei index (0.76±0.19 vs. 0.48±0.10, p<0.001), lower LVEF (63.8±7.0 vs. 67.3±5.6%, p<0.001) and lower absolute LV GLS (|LV GLS|) (17.0±4.2 vs. 19.7±3.3%, p<0.001) than controls. As the E-A summation occurred at lower heart rate, the |LV GLS| was also lower (p for trend=0.002).

Conclusions

The premature E-A summation at heart rates less than 100 bpm is associated with subclinical LV dysfunction. Time-based indices and LV GLS are helpful for evaluating this easily overlooked population.

Funding Acknowledgement

Type of funding sources: None.

Myocardial extracellular space expansion is related to burden of premature ventricular contractions in patients with hypertrophic cardiomyopathy without non-sustained ventricular tachycardia

Funding Acknowledgements

Type of funding sources: None.

Background

Current guidelines suggest the presence of non-sustained ventricular tachycardia (NSVT) as a risk factor of sudden cardiac death in patients with hypertrophic cardiomyopathy (HCM). However, high burden of premature ventricular contraction (PVC) may reflect myocardial fibrosis although the absence of NSVT.

Purpose

We investigated the association between PVC burden and myocardial extracellular space expansion in HCM patients without NSVT.

Methods

Of the 212 patients prospectively enrolled to the HCM registry of genetics, 84 patients were evaluated with both cardiac magnetic resonance and 24hr holter. Among them, 71 patients (58 males, mean age: 71 ± 13 years) have not been diagnosed with NSVT.

Results

Patients with NSVT (n = 13) showed more impaired LA functional indices and higher myocardial fibrosis burden compared with patients without NSVT (n = 71). Among patients who have not been diagnosed with NSVT, patients with late gadolinium enhancement (LGE, n = 46) had a higher total beats (109 ± 332 vs. 7 ± 13 beats per a day, p = 0.003) and burden (0.114 ± 0.225 vs. 0.008 ± 0.014 %, p = 0.003) of PVC during 24-hour compared with patients without LGE (n = 25). %LGE was correlated with total beats of PVC (r = 0.358, p = 0.002) and PVC burden (r = 0.377, p = 0.001). ECV also correlated with total beats of PVC (r = 0.387, p = 0.001) and PVC burden (r = 0.401, p = 0.001). The optimal cutoff value for PVC number was 45 (37.0% of sensitivity and 100% of specificity) with 0.733 of the area under the ROC curve (p < 0.001). Pathogenic or likely pathogenic sarcomere mutation was higher in NSVT group than no NSVT group (p < 0.05), and had a higher tendency in higher PVC burden group (0.05 < p < 0.1) than lower PVC burden group.

Conclusions

Total beats and burden of PVC are significantly related to increase in myocardial fibrosis in HCM patients without NSVT.

Abstract Figure. Mechanism of ventricular arrhythmia

Association of aortic plaque with intracranial atherosclerosis in patients with stroke

OBJECTIVE

To determine whether there is a relationship between aortic plaques and intracranial (IC) atherosclerosis.

METHODS

We reviewed 922 patients with stroke who had both transesophageal echocardiography and cerebral angiography. The plaques of these patients were classified as either complex aortic plaques (CAP), which protruded > or =4 mm or were present as mobile lesions in the proximal aorta, or simple aortic plaques (SAP), which were <4 mm or present in the descending aorta. Cerebral artery atherosclerosis was classified as either an IC or extracranial (EC) atherosclerosis.

RESULTS

Among the 922 patients, we found aortic plaques in 237 patients (26%). There were 111 (47%) patients of SAP, 74 (31%) patients with CAP, and 52 (22%) patients that had both SAP and CAP. Angiography showed IC or EC atherosclerosis in 511 patients (55%). The presence of aortic plaques was significantly associated with IC or EC atherosclerosis. The significance appeared to be due to the strong association between the presence of SAP and IC atherosclerosis (51% SAP vs 35% no plaques; odds ratio = 1.94, 95% CI: 1.17 to 3.21). In the multiple logistic regression analysis, SAP were independent predictors of IC atherosclerosis

CONCLUSIONS

The presence of simple aortic plaques may be a marker of advanced vascular disease. Detection of simple aortic plaques during transesophageal echocardiography may have clinical implications because patients with these plaques frequently had concomitant intracranial atherosclerosis, a risk factor for stroke.

Quantification of myocardial perfusion and determination of coronary stenosis severity during hyperemia using real-time myocardial contrast echocardiography

Although regional myocardial perfusion can be currently quantified with myocardial contrast echocardiography (MCE) by using intermittent harmonic imaging (IHI), the method is tedious and time-consuming in the clinical setting. We hypothesized that regional myocardial perfusion can be quantified and the severity of coronary stenosis determined during hyperemia with MCE using real-time imaging (RTI) where microbubbles are not destroyed. Six open-chest dogs were studied during maximal hyperemia induced by adenosine in the absence or presence of coronary stenoses varying from mild to severe. Myocardial blood flow (MBF) was measured at each stage by using radiolabeled microspheres. MCE was performed using both IHI and RTI. Data for the latter were acquired in both end-systole and end-diastole. No differences were found between myocardial flow velocity (MFV) derived from IHI and RTI when end-systolic frames were used for the latter. MFV was consistently higher for RTI (P <.01) when end-diastolic frames were used. A linear relation was noted between MFV and radiolabeled microsphere-derived MBF ratios from the stenosed and the normal beds when end-systolic frames were used for RTI (r = 0.78, P <.001), whereas no relation was found when end-diastolic frames were used (r = 0.08, P =.78). The scatter for assessing MBF (A.beta) was minimal for IHI and RTI (9%-10%) with end-systolic frames, whereas that for RTI with end-diastolic frames was large (30%). Furthermore the correlation with radiolabeled microsphere-derived MBF was significantly (P <.01) weaker with RTI when end-diastolic frames were used (r = 0.53) than when end-systolic frames (r = 0.94) or IHI was used (r = 0.99). Data acquisition for IHI was 10 minutes, whereas it was 8 seconds for RTI. Thus, RTI can be used to quantify regional myocardial perfusion and stenosis severity during MCE. Only end-systolic frames, however, provide accurate data. RTI offers a rapid and easy means of assessing regional myocardial perfusion with MCE.

Decrease in coronary blood flow reserve during hyperlipidemia is secondary to an increase in blood viscosity

BACKGROUND

During maximal hyperemia, capillaries provide the greatest resistance to flow. A major determinant of capillary resistance is viscosity. We, therefore, hypothesized that abnormal coronary blood flow (CBF) reserve observed during hyperlipidemia is secondary to increased blood viscosity and not abnormal coronary vasomotion.

METHODS AND RESULTS

Maximal hyperemia was induced in 9 dogs using adenosine. Serum triglyceride levels were increased by incremental doses of Intralipid. A good correlation was noted between serum triglyceride levels and blood viscosity (r=0.82). Neither total coronary blood volume nor myocardial blood volume changed with increasing serum triglyceride levels, indicating lack of vasomotion. Myocardial vascular resistance (MVR) increased with increasing triglyceride levels (r=0.84), while hyperemic myocardial blood flow (MBF) decreased (r=-0.64). The decrease in hyperemic MBF was associated with a decrease in blood velocity (r=-0.56). These findings were confirmed with direct intravital microscopic observations in the mice cremaster muscle.

CONCLUSIONS

Increasing lipid levels in a fully dilated normal coronary bed causes no change in large or small vessel dimensions. Instead, the increase in blood viscosity causes capillary resistance to rise, which attenuates hyperemic CBF. Therefore, the abnormal CBF reserve associated with hyperlipidemia is due to increase blood viscosity and not abnormal vascular function.

Quantification of cerebral perfusion with "Real-Time" contrast-enhanced ultrasound

BACKGROUND

No noninvasive technique is currently capable of "real-time" assessment and monitoring of cerebral blood flow (CBF). We hypothesized that cerebral perfusion could be accurately measured and monitored in "real time" with contrast-enhanced ultrasound (CEU).

METHODS AND RESULTS

Cerebral perfusion was assessed in 9 dogs through a craniotomy with CEU at baseline and during hypercapnia and hypocapnia while normoxia was maintained. Cerebral microvascular blood volume (A), microbubble velocity (beta), and blood flow (Axbeta) were calculated from time-versus-acoustic intensity relations. Compared with baseline, hypercapnia and hypocapnia significantly increased and decreased CBF, respectively, as measured by CEU. These changes in blood flow were mediated by changes in both A and beta. A good correlation was found between Axbeta derived from CEU and CBF measured by radiolabeled microspheres (y=0.67x-0.04, r=0.91, P<0.001).

CONCLUSIONS

Changes in both cerebral microvascular blood volume and red blood cell velocity can be accurately assessed with CEU. Thus, CEU has the potential for bedside measurement and monitoring of cerebral perfusion in real time in patients with craniotomies or burr holes.

Assessment of left atrial appendage filling pattern by using intravenous administration of microbubbles: comparison between mitral stenosis and mitral regurgitation

Mitral stenosis (MS) and mitral regurgitation (MR) are the most frequent conditions that cause a dilation and dysfunction of the left atrial appendage (LAA). Despite similarly dilated LAA in patients with MS and MR, the incidence of LAA thrombi and the risk of thromboembolism is different between these patients. The purpose of this study was to characterize the filling pattern of LAA by using intravenous administration of perfluorocarbon-exposed dextrose albumin (PESDA) during transesophageal echocardiographic examination in patients with MS and MR. Twenty-four patients with moderate to severe MS, 12 patients with severe MR, and a control group including 30 patients with conditions other than mitral valve disease underwent transesophageal echocardiographic examination with an intravenous bolus injection of PESDA. LAA emptying and filling velocities and maximal and minimal areas of LAA and LAA ejection fraction were measured. Digital gray-scale intensity (GSI) of the left atrial (LA) and LAA cavity after PESDA injection was measured by off-line analysis. Compared with control patients, patients with MS or MR had larger maximal and minimal areas of LAA and reduced LAA ejection fraction. LAA peak emptying flow velocity was significantly lower in patients with MS compared with those of MR or control patients. LAA peak filling velocity was significantly lower in patients with MS compared with that of control patients. However, there was no significant difference of LAA peak filling velocity between the patients with MS and MR. There was no significant difference of GSI ratio of LAA and LA between patients with MR and control patients; however, GSI ratio of LAA and LA was significantly lower in patients with MS compared with that of MR. The incidence of LAA spontaneous echo contrast and LAA thrombi in patients with MS was significantly higher than that of the patients with MR and control subjects (P <.005). Despite similarly dilated LAA area and depressed contractile function of LAA in patients with MS and MR compared with control patients, profoundly impaired LAA filling with resultant flow stasis was demonstrated by contrast echocardiography in patients with MS. These findings may explain the higher incidence of LAA spontaneous echo contrast and thrombus in patients with MS.

Flail aortic valve and acute aortic regurgitation due to spontaneous localized intimal tear of ascending aorta

This report describes the transesophageal echocardiographic findings of acute severe aortic regurgitation resulting from localized transverse intimal tear of ascending thoracic aorta which could not be suspected as a cause of flail aortic valve preoperatively. In patients with chest pain and acute aortic regurgitation associated with flail aortic valve, localized intimal tear of aorta should be considered as a possible cause of flail aortic valve.

Enhanced detection of right-to-left shunt through patent foramen ovale by transthoracic contrast echocardiography using harmonic imaging

When the results of transesophageal echocardiography was regarded as the gold standard for detecting a patent foramen ovale (PFO) in 136 consecutive patients referred for evaluation of cardiac source of embolism, transthoracic harmonic imaging using saline contrast was superior to fundamental imaging in accuracy for detecting a PFO (sensitivity, 22.5%; specificity [p < 0.05] and sensitivity, 100%; specificity 100%, respectively.)

Effects of left atrial compliance on left atrial pressure in pure mitral stenosis

In mitral stenosis (MS), left atrial (LA) pressure is commonly elevated because of increased LA afterload. There is a wide spectrum of LA pressure in patients with MS, however, despite a similar mitral valve orifice area. LA compliance is an important determinant of both cardiovascular performance and pathological physiology. Few data are available, however, regarding the effects of LA compliance on LA pressure. We hypothesized that LA pressure may be higher in patients with decreased LA compliance. We analyzed the right heart and transseptal catheterization data in 47 patients (41 female, mean age 40 +/- 10 years) with pure MS and sinus rhythm. The magnitude of LA a and v waves was measured from transseptal catheterization. Fick's method was used to determine cardiac output. LA compliance was calculated by dividing the systolic rise in LA pressure (DeltaP(LA) = P(LA(v)) - P(LA(x))) into the stroke volume. LA size, mitral valve area (MVA), mean diastolic pressure gradient (MG), left ventricular (LV) end-diastolic and end-systolic dimensions were obtained by using two-dimensional and Doppler echocardiography. Multiple regression analysis was performed to identify independent factors determining LA pressure. The mean MVA was 0.95 +/- 0.22 cm(2). MG and LA dimension were 11.2 +/- 5.2 mm Hg and 50.6 +/- 5.2 mm, respectively. The mean LA pressure and cardiac output obtained by cardiac catheterization were 23.4 +/- 8.4 mm Hg and 4.3 +/- 1.5 L/min, respectively. The calculated LA compliance was 4.9 +/- 2.8 cm(3)/mm Hg. Univariate analysis showed that factors associated with increased LA pressure were smaller MVA (r = -0.33, P < 0.05), higher MG (r = 0.69, P < 0.01) and lower LA compliance (r = -0.55, P < 0.01); among them, MG (beta coefficient 0.59, SE 0.19, P < 0.01) and LA compliance (beta coefficient -0.26, standard error 0.34, P < 0.05) were the strongest predictors of LA pressure. In conclusion, LA compliance, along with MG that reflects the severity of MS, is an important contributing factor determining LA pressure in patients with pure MS and sinus rhythm.

Assessment of elastic properties of the descending thoracic aorta by transesophageal echocardiography with acoustic quantification in patients with a stroke

Previous studies have described the use of transesophageal echocardiography (TEE) with acoustic quantification (AQ) in assessing aortic elastic properties. We hypothesized that patients with a prior history of stroke (ST) may have a higher risk of atherosclerotic change in great vessels compared to nonstroke subjects (NST) and thus have decreased elastic properties. We assessed the elastic properties of the descending thoracic aorta (DTA) by TEE in ST patients and compared them with data in NST patients. Subjects included 31 with ST without any evidence of emboli originating from the heart (age 51 +/- 10 years, M:F = 20:11) and 25 age-matched NST (M:F = 8:17). Patients with significant valvular heart disease including aortic and mitral regurgitation, left ventricular dysfunction (ejection fraction < 55%), and congenital heart disease were excluded. Compliance (C), distensibility (D), and stiffness index (SI) were measured using AQ and M-mode measurement at a level of the left atrium. We scored atherosclerotic risk factors (ARF) such as a history of diabetes, hypertension, smoking, hypercholesterolemia, and the presence of atheroma of DTA. There was no evidence of atheroma of DTA in NST. There were no significant differences in heart rate and systolic and diastolic blood pressure between ST and NST patients. Fractional area change (FAC) of DTA was significantly lower in ST than in NST patients (3.2 +/- 1.6 vs 5.4 +/- 2.5%, P = 0.000). ST patients had significantly lower C (1.2 +/- 0.4 vs 1.5 +/- 0.7 x 10(-3) cm2 mmHg(-1), P = 0.039), lower D (0.8 +/- 0.3 vs 1.5 +/- 0.8 x 10(-3) mmHg(-1), P = 0.000), and higher SI (10.3 +/- 8.8 vs 5.3 +/- 2.9, P = 0.006) than NST patients. ST patients without atheroma of DTA (n = 21) also had significantly lower C (1.1 +/- 0.4 vs 1.5 +/- 0.7 x 10(-3) cm2 mmHg(-1), P = 0.038) and lower D (3.5 +/- 1.4 vs 4.8 +/- 2.4 x 10(-3) mmHg(-1), P = 0.021) than NST patients. There was a significant positive correlation between SI and the score of ARF (r = 0.51, P = 0.000). The regional elastic properties of DTA measured by TEE with AQ and M-mode method were abnormal in ST. Therefore, TEE with AQ technique may have a possible clinical application for the detection of early atherosclerotic changes such as alteration of elastic properties in morphological normal DTA.

Enhanced detection of left atrial spontaneous echo contrast by transthoracic harmonic imaging in mitral stenosis

BACKGROUND

Spontaneous echo contrast (SEC) of the left atrium is associated with increased risk of thromboembolism in patients with mitral stenosis (MS). The determination of the presence and severity of left atrial (LA) SEC is of prognostic importance in these patients. Harmonic imaging (HI), a novel echocardiographic technique that differs from conventional fundamental imaging (FI) in that it involves transmitting ultrasound at one frequency and receiving at twice the transmitted frequency, produces better endocardial border definition and myocardial opacification. However, there are no data about its value for the detection of LA SEC. The purpose of this study was to investigate the utility of transthoracic noncontrast tissue HI in the detection of LA SEC in patients with MS.

METHODS

Seventy-four consecutive patients with MS (49 women, mean age 51 years) underwent standard transthoracic echocardiography (TTE) in both HI and FI modes and transesophageal echocardiography (TEE) to determine the presence and severity of LA SEC. Left atrial SEC was graded by TEE as either mild (only seen at high gain) or severe (visible in the entire left atrium at normal gain control of the equipment). The control group comprised 30 patients randomly selected from patients who did not have LA SEC at the TEE examination.

RESULTS

Atrial fibrillation was found in 46 patients (62.2%). The mean mitral valve area and mean mitral gradient were 1.0+/-0.3 cm(2) and 8.2+/-4.1 mm Hg, respectively. Nine patients (12.2%) had episodes of systemic embolism; 8 had stroke, and 1 had peripheral embolism. Left atrial thrombus was found in 11 patients (14.9%) by TEE. Left atrial SEC was present in all but one patient by TEE (mild in 35 patients, severe in 38). Fundamental imaging with TTE, however, revealed LA SEC in only 5 (6.8%) of the 73 patients. In contrast, with HI, LA SEC could be detected in 63 (86.3%) patients. In the detection of severe LA SEC, the sensitivities of FI and HI were 13.2% (5/38) and 100% (38/38), respectively. Left atrial SEC was not observed in control subjects by either FI or HI.

CONCLUSIONS

Transthoracic HI significantly enhances the detection of LA SEC in patients with MS.

Is the left atrial v. wave the determinant of peak pulmonary artery pressure in patients with pure mitral stenosis?

A large left atrial (LA) v. wave can be observed in patients with pure mitral stenosis (MS) because of decreased LA compliance. Few data are available regarding the relation between the magnitude of the LA v wave and pulmonary artery pressure in MS. We hypothesized that pulmonary artery pressure may be higher in patients with decreased LA compliance and thus a large v. wave. We analyzed the right-sided cardiac and transseptal catheterization data in 113 patients (16 men and 97 women, mean age 39 years) with pure rheumatic MS in sinus rhythm. Peak systolic, diastolic, and mean pulmonary artery pressures were measured with right-sided cardiac catheterization. The magnitude of LA a and v. waves were measured through transseptal catheterization. Two-dimensional and Doppler echocardiography were also performed to measure LA size, mitral valve area, mean mitral gradient, and valvular regurgitation. Multiple regression analysis was performed to identify the most important factor in the determination of pulmonary artery pressure. A large v wave, defined if peak v wave height exceeded the mean LA pressure by > or =10 mm Hg, was observed in 43 of 113 patients (38%). Increased pulmonary artery systolic pressure (> or =50 mm Hg) was observed in 38 patients (34%). Univariate analysis showed that the factors associated with increased pulmonary artery systolic pressure were smaller mitral valve area, higher mean mitral gradient, higher mean LA pressure, and higher LA v. wave; among them, LA v wave (p <0. 001) and mean mitral gradient (p<0.001) were significant independent factors for pulmonary artery systolic pressure in multivariate analysis. In conclusion, in patients with pure MS and sinus rhythm, the magnitude of the LA v. wave is strongly associated with pulmonary artery pressure. This finding may suggest that LA compliance is a major contributing factor determining pulmonary artery pressure in pure MS.

Assessment of myocardial metaiodobenzylguanidine uptake and its relation to left ventricular systolic and diastolic functional parameters in dilated cardiomyopathy

The purpose of this study was to assess the relation between myocardial metaiodobenzylguanidine (MIBG) uptake and left ventricular systolic and diastolic functional parameters, both of which are known as predictors of prognosis in patients with dilated cardiomyopathy. Echocardiography and iodine-123-MIBG myocardial scintigraphy were performed in 35 patients of dilated cardiomyopathy with normal sinus rhythm. Mean myocardial MIBG uptake in the patient group at early and delayed images were significantly lower than those in normal control subjects (10.6 +/- 1.1, 9.8 +/- 1.2 vs 12.4 +/- 1.0, 12.1 +/- 1.0, p < 0.01). There were, however, no significant differences of mean MIBG uptake in the lung and mediastinum between the two groups (p > 0.05). There were no significant correlations between myocardial MIBG uptake, expressed as the ratio of heart/mediastinum MIBG activity at delayed image, and left ventricular systolic and diastolic functional parameters [left ventricular ejection fraction, left ventricular end-diastolic dimension, peak velocity of early diastolic filling (E velocity), deceleration time of E wave, cardiac output, left ventricular end-diastolic pressure]. In conclusion, the myocardial uptake of MIBG is decreased in patients with dilated cardiomyopathy assessed by iodine-123-MIBG myocardial scintigraphy. There were, however, no significant correlations between myocardial MIBG uptake and left ventricular systolic and diastolic functional parameters derived from echocardiography.

Echocardiographic and morphologic characteristics of left atrial myxoma and their relation to systemic embolism

We examined the relation between the echocardiographic morphology of cardiac myxoma and systemic embolism in 25 patients. Two distinct types of myxoma could be identified by echocardiography: round type characterized by solid and round shape with nonmobile surface (n = 13, 52%), and polypoid type characterized by soft and irregular shape with mobile surface (n = 12, 48%); multiple regression analysis revealed the polypoid type of tumor was the only independent predictor of systemic embolism (p = 0.0029).

123I-MIBG myocardial scintigraphy as a noninvasive screen for the diagnosis of coronary artery spasm

BACKGROUND

It has been suggested that the sympathetic nervous system might play an important role in the development of coronary artery spasm. However, no cardiac imaging modality has been able to demonstrate abnormal sympathetic innervation in patients with coronary artery spasm. The purpose of this study was to assess the presence and location of abnormal sympathetic innervation using iodine 123-metaiodobenzylguanidine (123I-MIBG) single photon emission computed tomography (SPECT) and to evaluate the clinical efficacy of 123I-MIBG SPECT as a noninvasive screening test in patients with coronary artery spasm.

METHODS AND RESULTS

Coronary arteriography and a provocative test with intravenous administration of ergonovine maleate were performed in 26 patients (20 men, 6 women, mean age 48.2+/-12.0 years, range 20 to 67 years) who were suspected of having a coronary artery spasm. The subjects were divided into 2 groups: group 1 (n = 18) comprised subjects with a positive provocative test result, and group 2 (n = 8) comprised subjects with negative provocative test results. Ten healthy subjects served as controls. No abnormal MIBG uptake was observed in the control subjects. Abnormal sympathetic nervous innervation using 123I-MIBG SPECT was observed either as a reduced uptake or a defective pattern in the perfused areas in 13 of the 18 regions supplied by vessels of ergonovine-induced vasospasm. Normal sympathetic innervation, as evidenced by normal 123I-MIBG uptake, was noted in all of the 60 segments of normal vessel territories. Reduced uptake of 123I-MIBG was not detected in the perfused areas of 5 vasospasm-induced vessels (perfusion territory of left anterior descending coronary artery [LAD] and the right coronary artery [RCA] in 2 and 3 patients, respectively). The sensitivity and specificity of 123I-MIBG for detection of coronary artery spasm were 72.2% (95% confidence interval [CI] 55% to 89%) and 100%, respectively. The positive predictive and negative predictive values were 100% and 92.3% (95% CI 91% to 93%), respectively.

CONCLUSION

123I-MIBG SPECT is a feasible method to evaluate noninvasively and localize the territories of coronary arteries with spasm. Invasive diagnostic coronary arteriography with ergonovine provocation test may be unnecessary for diagnosis of coronary artery spasm in patients with typical resting pain, negative exercise test or normal thallium perfusion scan results, but showing abnormalities in 123I-MIBG SPECT.

Transesophageal echocardiographic identification of left upper pulmonary venous obstruction caused by compression by spontaneous pseudoaneurysm of the descending thoracic aorta

Pseudoaneurysm of the aorta usually occurs as a complication of nonpenetrating trauma or deceleration injuries. Spontaneous pseudoaneurysm of the aorta is, however, extremely rare. Pulmonary veins can be affected in this situation because of the anatomic proximity. However, it is often overlooked during clinical examination, during routine echocardiography, and even at invasive angiography. This report describes the importance of transesophageal echocardiography in the detection of pulmonary vein compression, which is not suspected during other noninvasive and invasive diagnostic tests, in a patient with spontaneous pseudoaneurysm of the descending thoracic aorta.

Index of myocardial performance using Doppler-derived parameters in the evaluation of left ventricular function in patients with essential hypertension

We analyzed Doppler echocardiographic data in 120 subjects with normal sinus rhythm; normals (NL, n = 60, ages 54.1 +/- 15.1) and essential hypertensive patients (HT, n = 60, ages 57.3 +/- 10.2). The IMP was calculated as follows: IMP = (ICT + IRT)/ET, ICT; isovolumic contraction time, IRT; isovolumic relaxation time, ET; ejection time. There were no significant differences in ejection fraction (EF), stroke volume index (SVI), cardiac index (CI), ET and ICT between NL and HT. There were, however, significant differences in deceleration time (DT), E/A ratio, IRT and the IMP between the two groups (199.5 +/- 45.6 msec vs 222.3 +/- 54.3 msec, p < 0.01; 1.4 +/- 0.7 vs 0.9 +/- 0.2, p < 0.01; 113.6 +/- 30.2 msec vs 134.2 +/- 29.6 msec, p < 0.01; 0.6 +/- 0.1 vs 0.8 +/- 0.3, p < 0.05). In HT, there were no differences in EF, SVI, CI, E/A ratio and DT between the NYHA I (Gp I, n = 36) and II (Gp II, n = 24) groups. However, ET of Gp II was significantly shorter than that of Gp I (259.4 +/- 43.5 msec vs 297.8 +/- 33.6 msec, p < 0.01). ICT, IRT and the IMP were significantly increased in Gp II, compared to those of Gp I (64.4 +/- 23.9 msec vs 89.4 +/- 46.2 msec, p < 0.05; 120.3 +/- 21.0 msec vs 155.2 +/- 28.5 msec, p < 0.001; 0.6 +/- 0.2 vs 1.0 +/- 0.4, p < 0.001). There were no differences in heart rate and mean blood pressure between Gp I and Gp II (70.9 +/- 11.4/min vs 66.3 +/- 11.4/min, p > 0.05; 138.4 +/- 21.2 mmHg vs 131.3 +/- 19.9 mmHg, p > 0.05). These data suggest that the IMP may be a useful parameter and an early indicator of left ventricular dysfunction in essential hypertensive patients with normal systolic function.

Real-time determination of left ventricular ejection fraction by automatic boundary detection in patients with dilated cardiomyopathy: a comparison with radionuclide ventriculography

Echocardiographic automatic boundary detection (ABD) is a new on-line technique which automatically outlines the left ventricular endocardial border and instantly calculates the left ventricular area and volume from two dimensional echocardiographic images. To determine if left ventricular ejection fraction (LVEF) can be derived using the ABD method, 25 consecutive patients with dilated cardiomyopathy, aged 52.1 +/- 15.2 (range 14 approximately 75), underwent complete echocardiographic examination with both the ABD method and radionuclide ventriculography (RVG). End-diastolic and end-systolic left ventricular areas were obtained on-line from the apical four chamber view. Left ventricular length was also measured from an apical view. Left ventricular volumes and ejection fraction were calculated using the single plane area-length method. ABD measurements could be obtained in all patients. Linear regression analysis compared ejection fraction derived by ABD and RVG. The mean radionuclide LVEF was 20.9 +/- 6.8% and mean ABD-derived LVEF was 22.7 +/- 5.8%. Linear regression analysis revealed that the ABD-derived LVEF is closely correlated with the RVG-derived LVEF (r = 0.87, p < 0.001). In conclusion, ABD echocardiography is a new on-line technique which may be used to accurately calculate LVEF in patients with dilated cardiomyopathy.