P244 BRISK WALKING CAN BE A MAXIMAL EFFORT IN HEART FAILURE PATIENTS. A COMPARISON OF CARDIOPULMONARY EXERCISE AND SIX–MINUTE WALKING TEST CARDIORESPIRATORY DATA

Aims

Cardiopulmonary exercise test (CPET) and six–minute walking test (6MWT) are frequently used in heart failure (HF). CPET is a maximal exercise, whereas 6MWT is a self–selected constant load test usually considered a submaximal, and therefore safer, exercise but this has not been tested previously. The aim of this study was to compare the cardiorespiratory parameters collected during CPET and 6MWT in a large group of healthy subjects and patients with HF of different severity.

Methods and Results

Subjects performed a standard maximal CPET and a 6MWT wearing a portable device allowing breath–by–breath measurement of cardiorespiratory parameters. HF Patients were grouped according to their CPET peak oxygen uptake (peakV̇O2). One–hundred and fifty–five subjects were enrolled, of whom 40 were healthy (59±8 years; male 67%) and 115 were HF patients (69±10 years; male 80%; left ventricular ejection fraction 34.6±12.0%). CPET peakV̇O2 was 13.5±3.5 ml/kg/min in HF patients and 28.1±7.4 ml/kg/min in healthy (p < 0.001). 6MWT–V̇O2 was 98±20% of the CPET peakV̇O2 values in HF patients, while 72±20% in healthy subjects (p < 0.001). 6MWT–V̇O2 was >110% of CPET peakV̇O2 in 42% of more severe HF patients (peakV̇O2<12ml/kg/min). Similar results have been found for ventilation and heart rate. Of note, the slope of the relationship between V̇O2 at 6MWT, reported as percentage of CPET peakV̇O2 vs. 6MWT V̇O2 reported as absolute value, progressively increased as exercise limitation did.

Conclusions

6MWT must be perceived as a maximal or even supra–maximal exercise activity at least in patients with severe exercise limitation from HF. Our findings should influence the safety procedures needed for the 6MWT in HF.

ROLE OF CARDIOPULMONARY EXERCISE TEST IN THE PREDICTION OF HEMODYNAMIC IMPAIRMENT IN PATIENTS WITH PULMONARY ARTERIAL HYPERTENSION

Periodic repetition of right heart catheterization (RHC) in pulmonary arterial hypertension (PAH) can be challenging. We evaluated the correlation between RHC and cardiopulmonary exercise test (CPET) aiming at CPET use as a potential noninvasive tool for hemodynamic burden evaluation. One hundred and forty‐four retrospective PAH patients who had performed CPET and RHC within 2 months were enrolled. The following analyses were performed: (a) CPET parameters in hemodynamic variables tertiles; (b) position of hemodynamic parameters in the peak end‐tidal carbon dioxide pressure (P_ETCO₂) versus ventilation/carbon dioxide output (VE/VCO₂) slope scatterplot, which is a specific hallmark of exercise respiratory abnormalities in PAH; (c) association between CPET and a hemodynamic burden score developed including mean pulmonary arterial pressure (mPAP), pulmonary vascular resistance (PVR), cardiac index, and right atrial pressure. VE/VCO₂ slope and peak P_ETCO₂ significantly varied in mPAP and PVR tertiles, while peak oxygen uptake (peak VO₂) and O₂ pulse varied in the tertiles of all hemodynamic parameters. P_ETCO₂ versus VE/VCO₂ slope showed a strong hyperbolic relationship (R² = 0.7627). Patients with peak P_ETCO₂ > median (26 mmHg) and VE/VCO₂ slope < median (44) presented lower mPAP and PVR (p < 0.005) than patients with peak P_ETCO₂ < median and VE/VCO₂ slope > median. Multivariate analysis individuated peak VO₂ (p = 0.0158) and peak P_ETCO₂ (p = 0.0089) as hemodynamic score independent predictors; the formula 11.584 − 0.0925 × peak VO₂ − 0.0811 × peak P_ETCO₂ best predicts the hemodynamic score value from CPET data. A significant correlation was found between estimated and calculated scores (p < 0.0001), with a precise match for patients with mild‐to‐moderate hemodynamic burden (76% of cases). The results of the present study suggest that CPET could allow to estimate the hemodynamic burden in PAH patients.

Cardiovascular death risk in mid-range ejection fraction heart failure: insights from cardiopulmonary exercise test

Background

The pivotal role of cardiopulmonary exercise testing (CPET) in the assessment of functional capacity and prognosis of patients with heart failure with reduced ejection fraction (HFrEF), either as a single CPET parameter (i.e. peak oxygen uptake, peak VO2), as a combination of CPET parameters (i.e. oxygen uptake at the anaerobic threshold (AT) and ventilatory efficiency (VE/VCO2 slope), or as a part of more comprehensive scores (i.e. Metabolic Exercise combined with Cardiac and Kidney Indexes, MECKI) is well established. Just few studies are available with respect a possible role of CPET in risk stratification of patients in HF with midrange EF (HFmrEF) subset, namely HF patients with LVEF between 40% and 49%.

Purpose

The aim of the present large Italian multicenter study was to characterize and to compare stable HFmrEF and HFrEF patients in terms of exercise capacity as well as of instrumental and laboratory variables. We analyzed a possible independent and incremental prognostic value of CPET parameters in identifying those HFmrEF patients at high cardiovascular death risk.

Methods

We retrospectively analyzed clinical and CPET data of stable HF patients with HFrEF and HFmrEF from the MECKI Score database. Five-thousand-seven-hundred-eleven patients, 4,535 with HFrEF and 1,176 with HFmrEF, were considered for the study. The end-point was cardiovascular death at 5 years. The median follow-up was 1343 days (25th–75th range, 627–2403 days).

Results

Cardiovascular death occurred in 552 HFrEF (12.2% event rate) and 61 HFmrEF (5.2% event rate) patients. At multivariate analysis, an independent role of variables included in the MECKI score (age, atrial fibrillation, LVEF, haemoglobin, sodium, MDRD, AT identification, VO2 at AT, peak VO2 also expressed as percentage of the maximum predicted, VE/VCO2 slope) was confirmed in HFrEF group (C-index=0.744) whereas, in the HFmrEF group, only age and peak VO2 remained outcome predictors (C-index=0.745).

We identified a peak VO2 &lt;55% of predicted and a VE/VCO2 slope &gt;31 as the most accurate cut-off values able to identify a HFmrEF subgroup with a cardiovascular mortality rate significantly higher than the overall HFmrEF (5.2% vs 8.5%) (Figure 1). By using both cut-off values contextually, we recognized a relatively small HFmrEF population with a cardiovascular risk quite similar to the HFrEF sample (11.4% vs 12.2%) (Figure 1).

Conclusions

Present data support the CPET as a useful tool in the HFmrEF management. Besides the peak VO2, which resulted as a strong independent outcome predictor, also a number of other CPET variables were associated to the cardiovascular death risk. Particularly, a peak VO2 ≤55% of the maximum and a VE/VCO2 slope ≥31 identified a HFmrEF subgroup of patients with a high cardiovascular death risk, similar to the one observed in the HFrEF group.

Funding Acknowledgement

Type of funding sources: None. Figure 1

Primary aldosteronism due to adrenocortical adenoma with concurrent ileum carcinoid tumor: case report

Primary aldosteronism (PA) with synchronous carcinoid syndrome is extremely rare occurrence. In this article, we describe a case of PA due to adrenocortical adenoma ("aldosteronoma") and concurrent malignant carcinoid tumor of ileum. The patient was treated with synchronous right adrenalectomy and resection of the ileum. This case is an example of concomitant presence of two types of tumors, effectively managed surgically. We report a case of a nonclassical form of multiple endocrine neoplasia type 1 (MEN 1) syndrome.

Detection of left ventricular systolic and diastolic abnormalities in patients with coronary artery disease by color kinesis

BACKGROUND

Color kinesis (CK) is a recently developed echocardiographic technique based on acoustic quantification that automatically tracks and displays endocardial motion in real time and has been used in initial studies to improve the evaluation of global and regional wall motion.

HYPOTHESIS

For further validation of the use of CK for analysis of segmental ventricular dysfunction, we assessed its sensitivity and specificity for detection of regional systolic and diastolic wall motion abnormalities in patients with coronary artery disease (CAD).

METHODS

Two-dimensional (2-D) echocardiography and CK were used to study 15 normal subjects and 63 patients with technically good quality echocardiographic tracings, who underwent coronary arteriography within 1 month of echocardiography. Significant (> 70% luminal diameter stenosis) CAD was present in 50 patients (79%).

RESULTS

Color kinesis tracked endocardial motion accurately in 93% of left ventricular segments. Wall motion score, systolic segmental endocardial motion (SEM), and the time of systolic SEM (tSEM) and diastolic (tDEM) segmental endocardial motion were calculated. Intra- and interobserver variability were within narrow limits. SEM and tSEM were significantly lower and tDEM was significantly higher in the patient population than in the control group (p < 0.001). Comparison between CK and 2-D echocardiography showed a correlation coefficient of 0.81 between the two techniques. The score was identically graded in 74% of segments, with concordance of 82% in diagnosing segments as abnormal. Interobserver concordance was 86% for CK (r = 0.85) and 81% for 2-D echocardiography (r = 0.80). The sensitivity and specificity of systolic and diastolic CK parameters for the detection of CAD were 88 and 92% and 77 and 85%, respectively. The positive predictive values were 93 and 96%, respectively, the negative predictive values were 63 and 73%, respectively, and the overall accuracy was 86 and 91%, respectively.

CONCLUSIONS

Our data suggest that CK is a feasible and sensitive technique for identifying regional systolic as well as diastolic wall motion abnormalities in patients with CAD.

Cushing's syndrome patient who exhibited congestive heart failure

Cushing's Syndrome (CS) may sometimes lead to dilated cardiomyopathy, even though this condition can be partially or completely reversed after treatment. In this article we report the case of a 28-yr-old woman with CS secondary to adrenal adenoma who exhibited congestive heart failure as an initial symptom. Two weeks before being admitted to our hospital, the patient started complaining of shortness of breath, orthopnea, paroxysmal nocturnal dyspnea and generalized edema. A physical examination did not reveal signs of hypercortisolism. Chest auscultation revealed bilateral diffused crepitation; blood pressure was 180/120 mmHg with heart rate of 90 beats/min. A chest X-ray showed a cardiac shade enlargement due to congestive heart failure. Transthoracic echocardiography demonstrated a dilated left ventricle and an impaired left ventricular systolic function. The patient's urinary cortisol excretion was elevated and circadian rhythm of cortisol was absent. ACTH level was low. In addition, plasma cortisol failed to decrease after administration of dexamethasone. An abdominal magnetic resonance imaging scan showed a 7-cm right adrenal mass. The patient was administered oxygen, spironolactone, ACE-inhibitor and the signs and symptoms of heart failure gradually improved. A laparoscopic right adrenalectomy was performed and pathological examination of the gland showed a benign adrenocortical adenoma. After the adrenalectomy the patient was started on hydrocortisone therapy and 5 months later the wall thickness of the left ventricle was within normal range and the patient's blood pressure was 130/80 mmHg. In conclusion we report the case of heart failure as the main clinical symptom in CS secondary to adrenal adenoma.

Increased plasma levels of adrenomedullin, a vasoactive peptide, in patients with end-stage pulmonary disease

AIM

To study adrenomedullin (AM) plasma levels in patients with severe lung disease and to analyze the relationship between AM and heart changes, hemodynamics and blood gases.

METHODS

Case control study of 56 patients (36 men, 20 women) with severe lung disease and 9 control subjects (7 men, 2 women). Patients with end-stage pulmonary disease, including chronic obstructive pulmonary disease (COPD, n=11), cystic fibrosis (CF, 26), idiopatic pulmonary fibrosis (ILD, n=9), and idiopatic pulmonary arterial hypertension (PAH, n=10), who were evaluated for lung trasplantation between January 1997 and September 2000, and nine patients who underwent lung surgery for a solitary benign nodule. AM plasma levels in pulmonary artery (mixed venous blood, vein) and aorta or femoral artery (arterial, art), art and vein blood gases, pulmonary hemodynamics, systemic hemodynamics, two-dimensional transthoracic echocardiography and echo-Doppler study.

RESULTS

Plasma AM (art and ven) levels were higher among patients' group compared to the controls (AMart p<0.02 and AMven p<0.04) for CF, ILD, PAH (AMart, pg ml(-1) Controls 13.7+/-3.6, COPD 22.8+/-6.2, CF 28.1+/-11.4, ILD 34.1+/-14.3, PAH 35.1+/-18.9; AMven, pg ml(-1) Controls 14.2+/-4.8, COPD 28.1+/-12.6, CF 31.7+/-14.1, ILD 38.7+/-16.5, PAH 40.1+/-4.4). We found with a trend towards higher concentration in ILD and PAH patients compared to COPD and CF but no statistical significant differences. Mixed-venous AM was higher than arterial AM in all groups resulting in AM uptake (AMPulmUp pg min(-1) Controls 4.8+/-22.6, COPD 21.1+/-44.9, CF 20.6+/-45.1, ILD 23.7+/-38.5, PAH 29.9+/-49.7). The univariate analysis showed a weak but significant correlation between AMart and mean systemic arterial pressure, heart rate, mean pulmonary arterial pressure and systemic vascular resistance. In the multivariate analysis, four variables emerged as independent factors of AMart including mean pulmonary arterial pressure, heart rate, mean systemic arterial pressure and left ventricular diastolic diameter (F=8.6, p<0.00001, r=0.60, r2=0.32). A similar weak correlation was apparent between AMven, systemic vascular resistance, and mean pulmonary arterial pressure. The results of multivariate analysis identify right atrial enlargement, mean right atrial pressure, heart rate and left ventricular dimensions as the only independent variables related to AMven (F=4.3, p<0.0004 r=0.56, r2=0.26). AM pulmonary uptake was significantly correlated with AMven (r=0.65), but not with hemodynamic, blood gas and echocardiographic variables.

CONCLUSIONS

AM plasma levels are elevated in patients with severe lung disease in face of a preserved pulmonary uptake. These results suggest that the high AM plasma levels in patients with severe lung disease are not caused by a reduced pulmonary clearance, instead suggesting a systemic production.

Long term treatment of pulmonary arterial hypertension with beraprost, an oral prostacyclin analogue

OBJECTIVE

To evaluate the effects of one year's treatment with beraprost, an orally active prostacyclin analogue, in patients with severe pulmonary hypertension.

PATIENTS

13 patients with severe pulmonary hypertension. This was primary in nine, thromboembolic in three, and caused by Eisenmenger syndrome in one.

METHODS

All patients underwent right heart catheterisation. Mean (SD) right atrial pressure was 5 (3) mm Hg, mean pulmonary artery pressure was 48 (12) mm Hg, cardiac index was 2.6 (0.8) l/min/m(2), and mixed venous oxygen saturation was 68 (7)%. Beraprost was started at the dose of 20 microgram three to four times a day (1 microgram/kg/day), increasing after one month to 40 microgram three to four times a day (2 microgram/kg/day), with further increases of 20 microgram three to four times a day in case of clinical deterioration.

MAIN OUTCOME MEASURES

New York Heart Association (NYHA) functional class, exercise capacity measured by distance walked in six minutes, and systolic pulmonary pressure (by echocardiography) were evaluated at baseline, after one month's treatment, and then every three months for a year.

RESULTS

After the first month of treatment, NYHA class decreased from 3.4 (0.7) to 2.9 (0.7) (p < 0.05), the six minute walking distance increased from 213 (64) to 276 (101) m (p < 0.05), and systolic pulmonary artery pressure decreased from 93 (15) to 85 (18) mm Hg (NS). One patient died after 40 days from refractory right heart failure, and another was lost for follow up at six months. The 11 remaining patients had persistent improvements in functional class and exercise capacity and a significant decrease in systolic pulmonary artery pressure in the period from 1-12 months. Side effects were minor.

CONCLUSIONS

Oral administration of beraprost may result in long lasting clinical and haemodynamic improvements in patients with severe pulmonary hypertension.

[Anatomico-functional changes in the right ventricle of the athlete]

The aim of this study was to compare the morpho-functional modifications of the right cardiac sections of the athlete's heart, with those of sedentary healthy control subjects. We studied 24 endurance athletes (mean age 28.17 +/- 7.28 years), 21 power athletes (mean age 25.86 +/- 4.96 years), and 20 sedentary healthy control subjects (mean age 33.22 +/- 6.67 years). We examined the right cavities by standard echocardiographic projections and the following parameters were evaluated: right ventricular longitudinal diameter; under tricuspid valve and medium ventricular transversal diameter immediately under the tricuspid plane and at medium ventricular level; right atrial transversal and longitudinal diameters. All parameters were corrected for body surface area. Our data showed that the right ventricle presents morphological adaptations to endurance exercise; modification is represented mainly by an increase in the mean transversal ventricular diameter with a consequent reduction in the transversal/longitudinal diameter ratio accompanied by modification of the ventricular geometry. In addition the data showed an increase in longitudinal and transversal diameters of the right atrium. On the contrary, the power athletes did not show statistical modification of the right ventricle and atrium. The different modifications of the right heart side diameter are probably due to the different hemodynamic loading, which is involved in the endurance and power training respectively.

Clinical impact of echocardiography in prognostic stratification after acute myocardial infarction

Risk stratification is mandatory in the management of the postinfarction period. The identification of high-risk patients, on the basis of clinical data (recurrent angina, overt heart failure, etc.), is quite easy, whereas stratification of uncomplicated subjects needs an accurate noninvasive strategy. In the last 20 years, echocardiography has been gaining an increasing role, allowing increasingly precise evaluation of infarct size. This detection of the extent of infarct size has a definite prognostic value. Since 1980, we have observed that a dysfunctioning left ventricular myocardium >40% marked patients with a poor prognosis. These observations are most important in asymptomatic infarct patients, in whom clinical features may not reflect the amount of left ventricular dysfunction. Our recent results on a large series of patients with acute myocardial infarction (MI) without overt heart failure have shown that the extension of wall motion abnormalities at 2-dimensional (2D) echocardiography was highly predictive of cardiac death or new coronary events in a 3-year follow-up (univariate analysis; p <0.0005). Echocardiography also plays an important role in detecting postinfarct ischemia, as seen by its wide use during stress tests. In our experience, the response to exercise echocardiographic testing has a high prognostic value. In fact, in our series, univariate analysis (Kaplan-Meier) showed that the best predictors of coronary events were the number of markers of ischemia during exercise (p <0.00001), the work load (p <0.00001), a positive exercise echo (p <0.0005), and the echo score at rest (p <0.0005). Multivariate analysis (Cox) confirmed these data: number of markers of ischemia: odds ratio (OR) 4.45, 95% confidence interval (CI) 1.5-13.1; work load: OR 2.46, CI 1.3-4.5; positive exercise echo OR 1.88, CI 1.1-3.2. Thus, serial echocardiography together with predischarge stress echocardiography is recommended for risk stratification after acute MI. In particular, in thrombolytic-treated patients, echo examinations allow the detection of functional recovery of viable reperfused myocardium whereas stress echo may show exercise-induced worsening in the region supplied by the infarct-related vessel, a predictor of a higher rate of coronary events.

Echocardiography in the coronary care unit: diagnostic and prognostic impact in comparison with clinical and other indicators

The clinical arena in which we must consider the role of echocardiography is characterized by 2 fundamental findings: (1) most patients with chest pain and suspected acute myocardial infarction (MI) do not present diagnostic electrocardiograms; and (2) an early and correct diagnosis is necessary to match the patient with the most adequate treatment. Echocardiography may be very useful in the coronary care unit, allowing a correct diagnosis of ischemic heart disease when electrocardiography is unclear, even before the rise of cardiac enzymes is detected. It may also play a role in decision-making for thrombolytic therapy. In addition, echocardiography provides useful information for early risk stratification. In fact, although high-risk patients are well identified by simple clinical or instrumental variables (i.e., Killip classification, enzymatic data, blood-gas analysis, electrocardiogram, etc.), most patients (>60%) are identified as low risk, and several subjects classified into the low-risk groups have a poor prognosis and are not detected using a single variable. In our experience, 2-dimensional echocardiography was able to further stratify between patients of low-risk classes. Therefore, echocardiography plays an important role in the early stratification of acute MI patients, especially in those without signs or symptoms of heart failure.

Assessment of left ventricular dyssynergy by color kinesis

Color kinesis is a new echocardiographic technique based on acoustic quantification. It has been developed to facilitate the ability to identify contraction abnormalities and has been incorporated into a commercially available ultrasound imaging system. The potential of this technique to improve the qualitative and quantitative assessment of wall motion abnormalities is described. Evaluation of color-encoded images allows detection of decreased amplitude of endocardial motion in abnormally contracting segments as well as a shorter time of endocardial excursion in segments with severely decreased motion. Compared with off-line quantitative studies, color kinesis has the advantage to be used on-line, without time-consuming manual tracing of endocardial boundaries. In addition, a single end-systolic color image contains the entire picture of spatial and temporal contraction and can be digitally stored and retrieved. In patients with proven coronary artery disease, color kinesis had a sensitivity of 88%, a specificity of 77%, and an overall accuracy of 86% in identifying the presence of segmental dysfunction. The practical application of color kinesis might be to improve our ability to distinguish normal from hypokinesis, something that has always been difficult in clinical echocardiography. Segmental analysis of color kinesis images allows objective detection of dobutamine-induced regional wall motion abnormalities in agreement with conventional visual interpretation of the corresponding 2-dimensional views. A method for objective assessment of wall dynamics during dobutamine stress echocardiography would be of particular clinical value, because these images are even more difficult to interpret than conventional echocardiograms. Quantitative assessment of diastolic function may allow objective evaluation of segmental relaxation abnormalities, especially under conditions of pharmacologic stress testing. Acquisition of color kinesis images during dobutamine stress echocardiography, both transthoracic and transesophageal, may facilitate the assessment of hybernating but viable myocardium and enhance the sensitivity in the detection of coronary artery disease.

Clinical and prognostic usefulness of supine bicycle exercise echocardiography in the functional evaluation of patients undergoing elective percutaneous transluminal coronary angioplasty

BACKGROUND

Supine bicycle exercise echocardiography (SBEE) has never been used before and early after percutaneous transluminal coronary angioplasty (PTCA) for assessing the functional outcome of the procedure and predicting late restenosis.

METHODS AND RESULTS

We selected 76 subjects with stable angina, normal wall motion at rest, and exercise-induced wall-motion abnormalities before PTCA. SBEE with peak exercise imaging and the use of a 16-segment, four-grade score model was performed 54 +/- 15 hours after PTCA. No exercise-related adverse events occurred. Patients were grouped according to SBEE results: group 1 (n = 35, 46%) with negative exercise ECG and echo; group 2 (n = 19, 25%) with a positive exercise ECG but normal echo; and group 3 (n = 22, 29%) with a positive exercise echo with either a positive (n = 7, 32%) or negative (n = 15, 68%) ECG. Exercise performance significantly improved in all groups. In group 3, peak wall-motion score index decreased from 1.27 +/- 0.11 before to 1.15 +/- 0.06 after PTCA (P < .05), and duration of wall-motion abnormalities went from 81 +/- 24 to 47 +/- 19 seconds (P < .05). The rate of clinical restenosis (ie, angina recurrence or positive 6-month SBEE in asymptomatic patients, both associated with angiographic restenosis > 50%) was 37%. By multiple logistic regression analysis, clinical restenosis was associated with a positive post-PTCA exercise echo (odds ratio [OR] 3.08, 95% confidence interval [CI] 1.66 to 5.72; P = .0004) and with increasing values of pre-PTCA wall-motion score index (OR 2.86, 95% CI 1.92 to 4.27; P = .005) and duration of wall-motion abnormalities (OR 2.12, 95% CI 1.07 to 4.20; P = .04).

CONCLUSIONS

SBEE is a safe and reliable tool to demonstrate changes in exercise-induced wall-motion abnormalities after PTCA and provides prognostic information in the risk assessment of clinical restenosis.

[At risk myocardium after acute infarct treated with fibrinolysis: assessment using exertion echocardiography and clinico-prognostic significance]

Several studies have been carried out on the role of exercise echocardiography for risk stratification after uncomplicated myocardial infarction. However, the diffusion of thrombolysis has entailed a remarkable change in the characteristics of these patients, with a major incidence of recurrent ischemic events or reinfarction in the follow-up. To test whether the predictive value of exercise echocardiography may be modified by thrombolytic treatment, we have studied 62 patients with acute myocardial infarction undergoing lytic therapy (Group A), compared to 153 conventionally-treated patients (Group B). All patients were asymptomatic at the time of the test, performed by cycloergometer 14 days after hospital admission. In 125 patients (47 Group A and 78 Group B) predischarge coronary angiography was performed. The exercise test showed a lower, but not significant, rate of positive tests in Group A patients (51.6 vs 58.8%). However, a positive test was more frequent in the homozonal area among patients who underwent thrombolytic therapy (50% of positive tests vs 18% in Group B; p < 0.001). Follow-up data (23 +/- 17 months) showed a higher but not significant rate of coronary events (cardiac death, reinfarction, severe angina, coronary bypass or angioplasty) in Group A patients with a positive test (62 vs 39% in Group B); however, in the subgroup with homozonal positive test, the event rate was much higher in Group A (77 vs 18% in Group B; p < 0.01). Furthermore, among patients with negative exercise test, coronary events were observed in 8% Group A and in 10% Group B patients. Therefore, our results show a higher percentage of homozonal exercise-induced ischemia with subsequent higher rate of coronary events in the thrombolyzed patients with respect to controls. This pattern is probably due to a higher rate of significant infarct-related residual stenosis, as coronary angiography have demonstrated. In conclusion, exercise echocardiography is useful in thrombolyzed patients, since it may better explore, rather than ECG, peri-necrotic areas.

Stress echocardiography: comparison of exercise, dipyridamole and dobutamine in detecting and predicting the extent of coronary artery disease

OBJECTIVES

This study was designed to compare exercise, dipyridamole and dobutamine echocardiography in the same patients and to evaluate, by measuring physiologic and echocardiographic variables, the mechanisms by which exercise and dobutamine induce ischemia.

BACKGROUND

The diagnostic value of stress echocardiography has been widely reported, but the specific effects of exercise, dipyridamole and dobutamine have not been directly compared. Furthermore, no echocardiography study has evaluated left ventricular volume changes at ischemic threshold during exercise and dobutamine administration.

METHODS

One hundred patients with suspected (Group A, n = 60) or known (Group B, n = 40) coronary artery disease underwent all three tests in random order.

RESULTS

In Group A, the sensitivities of exercise (mean 76%, 95% confidence interval [CI] 58% to 94%) and of dobutamine echocardiography (72%, 95% CI 53% to 91%) were higher than that of dipyridamole (52%, 95% CI 31% to 73%; p = 0.01 and p = 0.02, respectively). Specificity did not differ significantly among tests (94% for exercise [95% CI 86% to 100%] and 97% for dipyridamole and dobutamine [95% CI 91% to 100%]). Accuracy was identical for exercise and dobutamine (87%) and higher than that for dipyridamole (78%, p = 0.06). In Group B, the accuracy in predicting coronary disease extent was 71% for exercise, 33% for dipyridamole and 75% for dobutamine. At ischemic threshold, end-systolic volume index and the ratio of systolic blood pressure to end-systolic volume, a variable related to myocardial contractility, were significantly lower and higher, respectively, with dobutamine than during exercise (p < 0.05).

CONCLUSIONS

In a clinical setting, exercise echocardiography should represent the first diagnostic approach because it has high diagnostic efficacy and provides additional information on exercise capacity; pharmacologic stress, particularly that of dobutamine, provides a pivotal diagnostic tool when exercise is not feasible or its results are nondiagnostic. Our preliminary data on echocardiographic evaluation at ischemic threshold support the view that myocardial contractility is a major factor in inducing ischemia during dobutamine infusion.

[The efficacy of slow-release diltiazem in the treatment of stable angina of effort: a comparison between diltiazem and placebo]

The efficacy of a new slow release (SR) diltiazem preparation was assessed in 10 patients with stable effort angina. A double-blind, placebo controlled, randomized, crossover protocol was carried out comparing the effects of diltiazem 60 mg tid and diltiazem SR 120 mg bid on clinical and ergometric parameters. Exercise test was carried out 3 and 12 hours after the last dose of diltiazem or diltiazem SR respectively. Both drug preparations reduced the incidence of positive test, increased the exercise time and the time of onset of ischemic ST depression. The beneficial effects of the drugs appeared to be due to a reduction in myocardial oxygen consumption at the same workload as shown by the lesser value of pressure rate product at submaximal exercise. In conclusion, diltiazem SR at 12 hours after the last administration has the same effectiveness of diltiazem 60 mg at 3 hours.

[A non-Q wave myocardial infarct with an up or down shift of the ST segment in the acute phase: the clinical, echocardiographic, ergometric and coronary angiographic correlates]

To assess the significance of ST segment shift during the acute phase of non-Q myocardial infarction we studied the clinic echocardiographic, ergometric and coronarographic findings of 46 patients with a first non-Q wave myocardial infarction. The study population was subdivided in 2 subgroups on the basis of acute electrocardiographic change (Group I with ST elevation, Group II with ST depression). Patients with ST elevation had little myocardial infarction with enzymatic (early CPK peak) and coronarographic (low prevalence of coronary occlusion) signs of early spontaneous fibrinolysis. The second group had more diffuse myocardial infraction, higher prevalence of multivessel coronary disease and positive stress test. The ECG changes in this subgroup an probably due to subendocardial necrosis for the presence of collateral flow. The worse intrahospital prognosis of patients with ST segment depression may be related to cardiac function and age.

Identification of coronary artery by-pass grafts: reliability of MRI in clinical practice

In order to test MRI ability to detect the number and the sites of coronary artery by-pass grafts (CABGs), 22 patients with CABGs were studied. The detection of a neo-vessel in even one of the examination slices was considered as positive for the study, disregarding the difference between its origin and course. With such a criterion, MRI total percentage of vascular bridges identification resulted in 76.1% (51/67) with very low values for CABGs implanted on diagonal, obtuse marginal and posterior descending vessels (11/24 = 45.8%). These results lead to the conclusion that, although MRI has some advantages in the identification of CABGs implanted on the main coronary vessels in the early post-operative period, its extensive use cannot be proposed at the present state of the art.

Transesophageal dipyridamole echocardiography for diagnosis of coronary artery disease

The value of transthoracic dipyridamole echocardiography has been extensively documented. However, in some patients, because of a poor acoustic window, the rest transthoracic examination is not always feasible and the transesophageal approach is more convenient. Therefore, transesophageal echocardiography with high dose dipyridamole (up to 0.84 mg/kg body weight over 10 min) was performed in 32 patients in whom the transthoracic dipyridamole test either was not feasible (n = 29) or yielded ambiguous results (n = 3). The transesophageal echocardiographic test results were considered abnormal when new dipyridamole-induced regional wall motion abnormalities were observed. All 32 patients underwent coronary angiography; significant coronary artery disease was defined as greater than or equal to 70% lumen diameter narrowing in at least one major vessel. All patients also performed a bicycle exercise test 1 day before transesophageal dipyridamole echocardiography. Transesophageal stress studies were completed in all patients, with a maximal imaging time (in tests with a negative result) of 20 min. No side effects or intolerance to drug or transducer was observed. The left ventricle was always visualized in the four-chamber and transgastric short-axis views. High quality two-dimensional echocardiographic images were obtained in all patients both at rest and at peak dipyridamole infusion and were digitally analyzed in a quad-screen format. Coronary angiography showed coronary artery obstruction in 24 patients: 6 had single-, 9 double- and 9 triple-vessel disease. The transesophageal dipyridamole test showed a specificity of 100% and an overall sensitivity of 92%. The sensitivity of this test for single-, double- and triple-vessel disease was 67%, 100% and 100%, respectively.(ABSTRACT TRUNCATED AT 250 WORDS)

[Noninvasive determination of anaerobic threshold: validation of an automatic computerized method]

The Authors propose a computerized method in order to automatically detect the anaerobic threshold by the analysis of ventilatory parameters (VE, VO2). The algorithm calculates all possible linear fits and the relative standard error of the relationship between VE and VO2 beginning from the first set of 4 data (excluding the first 2 min of exercise) and increasing of 1 pair of data until peak exercise. Subsequently the program chooses the line that fits the greatest number of data with the smallest error. The ventilatory anaerobic threshold (SA Ve) is then calculated as the point at which the relationship between VE and VO2 is no more linear (i.e. when the VE measured gets over of 2 standard errors the calculated value on the basis of the regression formula). During the first phase of the study the method was validated against invasive AT determination by arterial lactate concentration (SA La) in 14 patients (7 athletes, 7 healthy sedentary subjects) during a symptom-limited ergospirometric test (in supine position, 10 W/min until exhaustion). Subsequently we studied the method repeatability in 20 men (10 normals, 10 patients with congestive heart failure who performed 2 ergospirometric tests on separate days. The results showed a good correlation when comparing each other the VO2 (SA Ve 26.88 +/- 4.24, SA La 25.95 +/- 3.88 ml/kg/min; r = 0.88) or the onset time (SA Ve 11.8 +/- 2.42, SA La 11.61 +/- 1.8 min; r = 0.91) of anaerobic threshold determined by the 2 methods.(ABSTRACT TRUNCATED AT 250 WORDS)

[Stratification of risk in infarcts without Q wave: role of echocardiography at rest and during exertion]

To assess the relation between the extent of myocardial necrosis and the presence of myocardium at risk in myocardial infarction without Q waves (NQMI) we studied by echocardiography the prevalence of jeopardized myocardium in a group of NQMI stratified on the basis of left ventricular wall motion (akinesis, hypokinesis, normal kinesis). We have studied 60 consecutive patients with non-Q myocardial infarction. Patients were examined by 2D echo at rest (V-VI day from the acute episode) and during symptoms limited bicycle ergometric test (ExT) (XX-XXX day). Regional left ventricular wall motion was evaluated as normal or asynergic (severe hypokinetic, akinetic) and the ExT was considered positive in case of new asynergic areas or ECG criteria. 2D echo at rest was technically satisfactory in 56 patients, 19 showed almost an akinetic segment (Aci) 17 had hypokinetic areas (Ipo) and 20 had normal left ventricle kinesis (Norc). Wall motion abnormalities were localized more frequently in the apex and lateral areas. During exercise 2D echo was performed in 46 patients (82%) with 23 positive tests (50%). Stratifying the population on the basis of left ventricle wall motion we observed a major number of positive tests in the group of patients with normal wall motion in comparison with those with asynergic areas at rest (Norc 66.6%, Ipo 35.7%, Aci 42.6% p less than 0.05 Nore vs Ipo and Nore vs Aci) despite the same CAD extension. These data show the heterogeneity of the NQMI that likely includes patients with transmural (asynergy group) and subendocardial MI (normal kinesis group), the latter with a higher degree of myocardium at risk.

Painless versus painful myocardial ischemia: different left ventricular dysfunction detected by echocardiography

The mechanism responsible for the absence of anginal pain in patients who have episodes of both painless and painful myocardial ischemia, still remains unknown. Does the pain depend on an overstimulation of receptive structures or is this symptom the product of the excitation of a well-defined receptive system? The aim of this work is to test the first hypothesis: whether silent attacks are accompanied by the same degree of mechanical impairment as symptomatic ones. The authors compared the echocardiographic left ventricular functional behavior in the same patient (6 patients) during painful and painless myocardial ischemia. The echocardiographic changes observed during silent ischemic attacks were significantly different from those detected during symptomatic attacks. The latter were characterized by a larger extension of the ischemic myocardium and, as a consequence, by a larger functional impairment. Symptomatic and asymptomatic ischemic attacks were recorded echocardiographically in the same patient during repeated attacks on the same day, and were always clearly differentiated by the degree of wall motion abnormalities. The echocardiographic monitoring during the ischemic attack seemed to confirm that the greater functional impairment preceded the onset of pain leading to the occurrence of this symptom. Nevertheless, it was impossible to identify a threshold value above which the ischemic attack will be symptomatic. Our data seem to indicate a close relationship between painful ischemia and a higher degree of ischemic damage. Thus, in patients with predominantly painful myocardial ischemia, the extension and the severity of ischemia could play an important role in determining this symptom.

Left ventricular filling pattern in hypertensive patients after reversal of myocardial hypertrophy

After treatment with alpha-methyldopa a regression of left ventricular hypertrophy, due to hypertension, has been reported in spontaneously hypertensive rats. The reduction of left ventricular mass has been associated with an increase in hydroxyproline concentration, suggesting secondary functional changes. On this basis, 12 patients with essential hypertension and echocardiographic evidence of left ventricular hypertrophy have been studied before and after a 6-month alpha-methyldopa treatment. Ten normal subjects were used as a control group. Curves of changes in left ventricular diameter and velocity curves were obtained by digitation of the M-mode endocardial echoes and the diastolic patterns were studied. Before treatment all patients, as compared to normal subjects, showed: (a) prolongation of the isovolumetric relaxation time index, with increased diameter changes; (b) reduction of diameter changes and peak velocity during the rapid filling; and (c) marked compensatory increase of diameter changes and peak velocity of the filling due to atrial systole. Left ventricular hypertrophy was reduced in 5 patients (first group) after treatment. This group showed: (a) normalization of the isovolumetric relaxation time index; (b) slight increase of diameter changes during rapid filling; (c) increased peak velocity of the rapid filling; and (d) reduction of diameter changes and peak velocity during atrial systole. No changes of functional data were observed in the other 7 patients (second group) in whom left ventricular hypertrophy was unchanged after treatment. It is shown how the reduction of left ventricular hypertrophy, per se, could induce such an improvement of diastolic function, despite the biochemical changes probably caused by administration of alpha-methyldopa.

Echocardiographic assessment of congenital mitral stenosis

To assess the severity and precise anatomy of congenital mitral stenosis (MS), 17 patients with congenital left ventricular inflow obstruction were studied by M-mode and two-dimensional echocardiography (2DE) and by cardiac catheterization. In six patients MS was an isolated lesion and in 11 it was combined with other cardiovascular malformations. The diagnosis was confirmed at operation or autopsy in 15 patients. Twenty normal subjects of the same age and sex were selected as controls. M-mode amplitude and speed of diastolic closure (E-F slope) of the anterior mitral valve leaflet were determined in all patients. Mitral valve areas were traced after careful short-axis 2DE scans in 15 patients. Supravalvar, valvar, or subvalvar obstruction was evaluated in patients with surgical or autopsy documentation. Analysis of M-mode echocardiograms showed a reduction of E-F slope in all patients compared to normal control subjects but a poor correlation between E-F slope and hemodynamic data (mitral valve areas or pressure gradients). Diastolic fluttering of either or both mitral valve leaflets was found in 12 patients. It is concluded that M-mode echocardiography may be useful for qualitative assessment of congenital MS, even in the presence of associated heart defects, but less useful in evaluating its severity. Analysis of 2DE revealed good correlation between mitral valve areas as calculated with 2DE and with the Gorlin formula at cardiac catheterization, despite the complexity of the congenital mitral lesion. Anatomic varieties of congenital left ventricular inflow obstruction, such as stenosing supravalvar mitral ring or parachute deformity of the mitral valve, were recognized at 2DE.(ABSTRACT TRUNCATED AT 250 WORDS)