Enhanced resolution of random amplified polymorphic DNA genotyping of Pseudomonas aeruginosa.

AIMS: To develop a rapid, sensitive and reproducible screening test for the detection of nosocomial spreading of Pseudomonas aeruginosa. METHODS AND RESULTS: Ps. aeruginosa genomic DNA extraction, RAPD-PCR, electrophoresis on acrylamide gel and silver staining were performed by using standardized reagents and conditions. The results were compared with the agarose gel electrophoresis followed by ethidium bromide staining. CONCLUSIONS: The coupling of acrylamide gel electrophoresis and silver staining gave about 80% more DNA bands than the traditional method, allowing a finer discrimination among different Ps. aeruginosa strains. SIGNIFICANCE AND IMPACT OF THE STUDY: By enhancing the resolution of the electrophoretic separation and the sensitivity of the staining, random amplification could be easily applied to the surveillance and prevention of nosocomial infections by clinical microbiology laboratories.

Prognostic significance of the dobutamine echocardiography test in idiopathic dilated cardiomyopathy.

Dobutamine stress echo provides potentially useful information on idiopathic dilated cardiomyopathy (IDC). From February 1, 1997, to October 1, 1999, 186 patients (131 men and 55 women, mean age 56 +/- 12 years) with IDC, ejection fraction <35%, and angiographically normal coronary arteries were studied by high-dose (up to 40 micro/kg/min) dobutamine echo in 6 centers, all quality controlled for stress echo reading. In all patients, wall motion score index (WMSI) (from 1 = normal to 4 = dyskinetic in a 16- segment model of the left ventricle) was evaluated by echo at baseline and peak dobutamine. One hundred eighty-four patients were followed up (mean 15 +/- 13 months) and only cardiac death was considered as an end point. There were 29 cardiac deaths. Significant parameters for survival prediction at univariate analysis are: DeltaWMSI (chi-square 20.1; p <0.0000), New York Heart Association (NYHA) class (chi-square 17.57; p <0.0000), rest ejection fraction (chi-square 10.41; p = 0.0013), angiotensin-converting enzyme inhibitors (chi-square 8.23; p = 0.0041), and hypertension (chi-square 8.08, p = 0.0045). In the multivariate stepwise analysis only DeltaWMSI and NYHA were independent predictors of outcome (DeltaWMSI = hazard ratio 0.02, p < 0.0000; NYHA class = hazard ratio 3.83, p < 0.0000). Kaplan-Meier survival estimates showed a better outcome for patients with a large inotropic response (DeltaWMSI > or =0.44, a cutoff identified by receiver-operating characteristic curves analysis) than for those with a small or no myocardial inotropic response to dobutamine (93.6% vs 69.4%, p = 0.00033). Thus, in patients with IDC, an extensive contractile reserve identified by high-dose dobutamine stress echocardiography is associated with a better survival.

The incremental prognostic value of pharmacological stress echo over exercise electrocardiography in women with chest pain of unknown origin.

AIMS: The value of exercise electrocardiography in evaluating women with suspected coronary artery disease is limited. Conversely, stress echocardiography is effective for both diagnostic and prognostic purposes in females. The purpose of the study was to determine the relative prognostic value of exercise electrocardiography and pharmacological stress echocardiography in a cohort of women with chest pain of unknown origin, in order to verify whether criteria could be established for the daily non-invasive evaluation of such a low-risk profile population. METHODS AND RESULTS: Exercise electrocardiography and pharmacological stress echocardiography (171 dipyridamole, 73 dobutamine) were performed in 244 women (age 60+/-10 years) with chest pain and known coronary artery disease. A positive result of exercise electrocardiography (ST-segment shift > or =1 mm at 80 ms after the J point) was detected in 95 patients; a positive result of stress echocardiography (new regional wall motion abnormalities) was observed in 33 patients. During follow-up (36+/-18 months), two deaths, five infarctions, seven unstable anginas, and 11 coronary revascularizations occurred. Using Cox analysis, the positive result of stress echocardiography (odds ratio=40.1) alone, was independently related to hard cardiac events (death, infarction). With spontaneous cardiac events (death, infarction, and unstable angina) as end-points, the multivariate prognostic predictors were a positive result of stress echocardiography (odds ratio=37.0), a family history of coronary artery disease (odds ratio=4.1), typical chest pain (odds ratio=3.7), and a positive exercise electrocardiography result with a rate-pressure product < or =20 000 (odds ratio=3.5). By adopting an interactive stepwise procedure, the prognostic value of stress echocardiography was incremental to that of clinical and exercise electrocardiography data. Nevertheless, the negative result of exercise electrocardiography and pharmacological stress predicted a very high and comparable (P=ns) 24-month survival rate when both hard and spontaneous cardiac events were taken as end-points. CONCLUSIONS: In women with chest pain, stress echocardiography is a strong and independent prognostic indicator, incremental to that shown by exercise electrocardiography. However, the two tests have a similar high negative predictive value in this population. Therefore, exercise electrocardiography has to be considered the initial approach and the only test when the result is negative, whereas stress echocardiography is warranted in selected conditions, including those in women with uninterpretable electrocardiograms, those unable to exercise maximally, and those with an ambiguous or ischaemic response to exercise electrocardiography.

Madness and method in stress echo reading.

AIM: To assess whether 'eye education' through short-term, high-intensity joint reading sessions may improve diagnostic accuracy and inter-observer agreement among beginners. METHODS AND RESULTS: Seventeen cardiologists with absent to minimal (<100 studies performed) previous stress echo experience independently and blindly read 18 stress echo studies, nine at the beginning ('pre-training' set) and nine at the end ('post-training' set) of a 2 day stress echo school which included a joint reading session of 50 tapes. The two sets were balanced as far as type of stress and image quality. The 17 observers had an average accuracy score of 51+/-16.4 before and 64.3+/-8.7% after the training (P<0.005). Concordant (i.e. >14 readers giving the same response) interpretation occurred in three out of nine studies before and in eight out of nine studies after the training (33% vs 88%, P<0.01). Kappa values went from 0.14 (poor) before to 0.39 (fair, close to moderate) after the training. CONCLUSION: Short-term, high-intensity dedicated training in stress echo, with joint reading sessions and consensus development of reading criteria significantly increased accuracy and markedly reduced the inter-observer variability in the reading of stress echoes by beginners. If there is a Shakespearean madness in stress echo reading, 'yet there is a method in't' (Hamlet, II, II, 205-206).

Prognostic value of pharmacological stress echocardiography in women with chest pain and unknown coronary artery disease.

OBJECTIVES: In this study we sought to investigate the prognostic value of pharmacological stress echocardiography in women referred for chest pain, having unknown coronary artery disease. BACKGROUND: The noninvasive identification of a high-risk subgroup among women with chest pain and unknown coronary artery disease is an unresolved task to date. METHODS: A total of 456 women (mean [+/-SD] age 63+/-10 years) underwent pharmacological stress echocardiography with either dipyridamole (n = 305) or dobutamine (n = 151) for evaluation of chest pain and were followed-up for 32+/-19 months. None of them had a previous diagnosis of coronary artery disease. RESULTS: No major complication occurred during stress testing. Five tests (1.1%) were prematurely interrupted because of the appearance of side effects. Echocardiographic positivity was identified in 51 patients. During the follow-up, 23 cardiac events occurred: 3 deaths, 10 infarctions and 10 cases of unstable angina; an additional 21 patients underwent coronary revascularization. At Cox analysis, the echocardiographic evidence of ischemia was found as the only independent predictor of hard cardiac events (death, infarction) (odds ratio [OR] = 27.5; 95% confidence interval [CI] = (6.5 to 115.5; p = 0.0000). When spontaneous cardiac events (death, infarction and unstable angina) were considered as endpoints, the positive echocardiographic result (OR = 23.9; 95% CI = 8.6 to 66.8; p = 0.0000) and family history of coronary artery disease (OR = 3.7; 95% CI = 1.5 to 9.1; p = 0.0037) were independently correlated with prognosis. By using an interactive stepwise procedure, the prognostic value of stress echocardiography was found to be incremental to that provided by clinical variables, both considering hard and spontaneous cardiac events as endpoints. The 3-year survival rate for the negative and the positive population was respectively, 99.5% and 69.5% (p = 0.0000) considering hard cardiac events, 99.2% and 50.6% (p = 0.0000) considering spontaneous cardiac events. CONCLUSIONS: Pharmacological stress echocardiography is safe, highly feasible and effective in risk stratification of women with chest pain and unknown coronary artery disease, also when hard endpoints are considered. Its use can have relevant implications in daily clinical practice for selection of patients needing further investigations.

Prognostic value of myocardial viability in medically treated patients with global left ventricular dysfunction early after an acute uncomplicated myocardial infarction: a dobutamine stress echocardiographic study.

BACKGROUND: Residual viable myocardium identified by dobutamine stress after myocardial infarction may act as an unstable substrate for further events such as subsequent angina and reinfarction. However, in patients with severe global left ventricular dysfunction, viability might be protective rather than detrimental. The aim of this study was to assess the impact on survival of echocardiographically detected viability in medically treated patients with global left ventricular dysfunction evaluated after acute uncomplicated myocardial infarction. METHODS AND RESULTS: The data bank of the large-scale, prospective, multicenter, observational Echo Dobutamine International Cooperative (EDIC) study was interrogated to select 314 medically treated patients (271 men; age, 58+/-9 years) who underwent low-dose (1.6). Patients were followed up for 9+/-7 months. Low-dose dobutamine stress echocardiography identified myocardial viability in 130 patients (52%). Dobutamine-atropine stress echocardiography was positive for ischemia in 148 patients (47%) and negative in 166 patients (53%). During the follow-up, there were 12 cardiac deaths (3.8% of the total population). With the use of Cox proportional hazards model, delta low-dose WMSI (the variation between rest WMSI and low-dose WMSI) was shown to exert a protective effect by reducing cardiac death by 0.8 for each decrease in WMSI at low-dose dobutamine (coefficient, -0.2; hazard ratio, 0.8; P<0.03); WMSI at peak stress was the best predictor of cardiac death in this set of patients (hazard ratio, 14.9; P<0.0018). CONCLUSIONS: In medically treated patients with severe global left ventricular dysfunction early after acute uncomplicated myocardial infarction, the presence of myocardial viability identified as inotropic reserve after low-dose dobutamine is associated with a higher probability of survival. The higher the number of segments showing improvement of function, the better the impact is of myocardial viability on survival. The presence of inducible ischemia in this set of patients is the best predictor of cardiac death.

Effects of antianginal therapy with a calcium antagonist and nitrates on dobutamine-atropine stress echocardiography. Comparison with exercise electrocardiography.

BACKGROUND: Anti-ischaemic therapy with nitrates and/or calcium channel blockers profoundly affects the results of pharmacological stress echocardiography with coronary vasodilators but the influence on catecholamine stress testing remains unsettled. AIMS: The present study aimed to assess the effects of non-beta-blocker antianginal therapy on dobutamine (up to 40 micrograms.kg-1.min-1)-atropine (up to 1 mg) stress. echo-cardiography and to evaluate whether drug-induced changes in the dobutamine atropine stress echocardiography response may predict variations in exercise tolerance. METHODS: Twenty six patients with angiographically assessed coronary artery disease (seven patients with single-, 10 with double-, and nine with triple-vessel disease) performed a dobutamine atropine stress echocardiography and an exercise electrocardiography test in random order both off and on antianginal drugs (nitrates and calcium antagonists). In doubtamine-atropine stress echocardiography, we evaluated: dobutamine time (i.e. the time from initiation of the dobutamine infusion to obvious dyssynergy), wall motion score index (in a 16-segment model of the left ventricle, each segment ranging from 1 = normal, to 4 = dyskinetic), and rate-pressure product at peak stress. RESULTS: Dobutamine-atropine stress echocardiography positivity occurred in 26 out of 26 patients off and in 23 patients on therapy (100 vs 88%, P = ns). Atropine coadministration was needed to evoke echo positivity in no patient off and in five out of 26 on therapy (0 vs 19% P < 0.01). The achieved rate pressure product during dobutamine-atropine stress echocardiography was comparable on and off therapy (17 +/- 4 vs 19 +/- 5 x 10(3) mmHg x heart rate. min-1, P = ns). Therapy induced an increase in dobutamine time (on = 16 +/- 3 vs of = 13 +/- 3 min, P < 0.01) and a decrease in peak wall motion score index (on = 1.3 +/- 0.2 vs off = 1.5 +/- 0.3, P < 0.01). The therapy induced changes in exercise time during the exercise electrocardiography test were not significantly correlated to dobutamine-atropine stress echocardiography variations in either dobutamine time (r = 0.07, P = ns), or peak rate pressure product (r = 0.24, P = ns), or peak wall motion score index (r = 0.02, P = ns). CONCLUSIONS: (1) non-beta-blocker antianginal therapy only modestly reduces dobutamine-atropine stress echocardiography sensitivity, although atropine coadministration is more often required to reach stress echo positivity under therapy; (2) therapy reduces the severity of dobutamine atropine stress echocardiography ischaemia stratified in the time and space domain, but these changes are only poorly correlated to variations in exercise tolerance.

Prognostic value of dobutamine-atropine stress echocardiography early after acute myocardial infarction. Echo Dobutamine International Cooperative (EDIC) Study.

OBJECTIVES: The aim of this multicenter, multinational, prospective, observational study was to assess the relative value of myocardial viability and induced ischemia early after uncomplicated myocardial infarction. BACKGROUND: Dobutamine-atropine stress echocardiography allows evaluation of rest function (at baseline), myocardial viability (at low dose) and residual ischemia (peak dose, up to 40 micrograms with atropine up to 1 mg) in one test. METHODS: Dobutamine-atropine stress echocardiography was performed 12 +/- 5 days (mean +/- SD) after a first uncomplicated acute myocardial infarction in 778 patients (677 men; mean age 58 +/- 10 years) with technically satisfactory rest echocardiographic study results. Patients were followed-up for 9 +/- 7 months. RESULTS: Dobutamine-atropine stress echocardiographic findings were positive for myocardial ischemia in 436 of patients (56%) and negative in 342 (44%). During follow-up, there were 14 cardiac-related deaths (1.8% of the total cohort), 24 (2.9%) nonfatal myocardial infarctions and 63 (8%) hospital readmissions for unstable angina. One hundred seventy-four patients (22%) underwent coronary revascularization (bypass surgery or coronary angioplasty). Spontaneous events occurred in 61 of 436 patients with positive and 40 of 342 patients with negative findings on dobutamine-atropine stress echocardiography (14% vs. 12%, p = 0.3). When only spontaneously occurring events were considered, the most important predictor was myocardial viability (chi-square 9.7). Using the Cox proportional hazards model, only the presence of myocardial viability (hazard ratio [HR] 2.0, p < 0.002) and age (HR 1.03, p < 0.001) were predictive of spontaneously occurring events. When only hard cardiac events were considered, age was the strongest predictor (chi-square 3.6, p = 0.056), followed by wall motion score index (WMSI) at peak dose (chi-square 3.3, p = 0.06) and remote ischemia (chi-square 2.25, p = 0.1). When cardiac death was considered, WMSI at peak dose was the best predictor (HR 9.2, p < 0.0001). CONCLUSIONS: During dobutamine stress, echocardiographic recognition of myocardial viability is more prognostically important than echocardiographic recognition of myocardial ischemia for predicting unstable angina, whereas WMSI at peak stress was the best predictor of cardiac-related death. Different events can be recognized with different efficiency by various stress echocardiographic variables.

Dipyridamole echocardiography for diagnosis of coexistent coronary artery disease in hypertrophic cardiomyopathy. Echo-Persantine International Cooperative (EPIC) Study Group--Subproject Hypertrophic Cardiomyopathy.

The recognition of coexistent coronary artery disease (CAD) in patients with hypertrophic cardiomyopathy may be difficult by noninvasive testing based upon electrocardiographic changes or perfusion defects. Dipyridamole-stress echocardiography has proved a sensitive and highly specific test for noninvasive diagnosis of CAD in various patient subsets. To establish the feasibility, safety, and diagnostic accuracy of dipyridamole-stress echocardiography in patients with hypertrophic cardiomyopathy, we performed high-dose dipyridamole testing (up to 0.84 mg/kg over 10 minutes) in 88 patients with hypertrophic cardiomyopathy (63 men; mean age +/- SD, 46 +/- 17 years). A subset of 60 patients was referred for coronary angiography independently of test results; CAD was defined as > or = 50% diameter narrowing in at least 1 major coronary vessel. Dipyridamole echocardiography/electrocardiography testing was completed in all patients, with no limiting side effects or adverse reactions. In the subgroup of 60 patients with coronary angiography (14 with and 46 without CAD), chest pain occurred in 18 patients (8 with and 10 without CAD, p = NS); ST-segment depression > or = 2 mm from baseline in 28 (7 with and 21 without CAD, p = NS); and transient dyssynergy in 10 patients (10 with and none without CAD, p < 0.0001). Assuming the transient regional dyssynergy to be the only criterion of positivity, the dipyridamole echocardiography test showed 71% sensitivity, 100% specificity, 100% positive predictive value, and 93% diagnostic accuracy for diagnosis of angiographically assessed CAD. We conclude that high-dose dipyridamole echocardiography testing may be considered a feasible and accurate tool for the noninvasive diagnosis of CAD in patients with hypertrophic cardiomyopathy.

[Acute ischemia in myocardial hypertrophy: a report of 2 clinical cases]. / Ischemia acuta nell'ipertrofia miocardica: descrizione di due casi clinici.

We report two cases presented with a clinical picture of acute myocardial ischemia, chest pain and giant negative T waves on electrocardiogram (absent in previous tracings). The echocardiogram B-Mode showed in both cases an asymmetric left ventricular hypertrophy caused, respectively, by hypertrophic cardiomyopathy and hypertensive heart disease. Short-term electrocardiographic evolution to complete normalization was observed in both cases. The echo-dipyridamole test did not show dissynergias and this fact suggested the absence of coronary artery disease; this hypothesis was confirmed by a normal coronary angiography. We suppose that in both patients a few factors contributed to the ischemic events: respectively an acute anemia due to gastric bleeding and high blood pressure values. This clinical presentation is an example of a difficult differential diagnostic problem between left ventricular hypertrophy and acute myocardial ischemia, as it shows that giant negative T waves in hypertrophic cardiomyopathy do not necessarily depend on left myocardial hypertrophy involving the apex or other segments but may be associated to an acute myocardial ischemia related or not to a coronary artery disease. A correct evaluation of these clinical cases is important for clinical, therapeutic and prognostic implications.

Severity of arrhythmias and extent of hypertrophy in hypertrophic cardiomyopathy.

To evaluate the relationship between the extent of left ventricular hypertrophy and ventricular or atrial arrhythmias, 77 patients with hypertrophic cardiomyopathy underwent two-dimensional echocardiography and 24-hour Holter monitoring. Antiarrhythmic treatment was discontinued before the study. Hypertrophy was septal in 33 patients, "extensive" (i.e., involving the septum and free wall) in 38 patients, and predominantly apical in six patients. Lown grade I and II ventricular arrhythmias were detected in 37% of patients, grade III in 21%, and grade IV in 29%. Atrial extrasystoles were seen in 52% of patients and chronic atrial fibrillation in 13%. More serious ventricular arrhythmias (Lown grades III and IV) occurred significantly more frequently in patients with extensive than in those with only septal hypertrophy (22/38 vs 11/33; p less than 0.001); similarly, chronic atrial fibrillation occurred more commonly in those with extensive hypertrophy (9/38 vs 1/33; p less than 0.01). During a mean follow-up period of 2.6 years, three patients died. All had a pattern of extensive hypertrophy. Two of them had ventricular tachycardia and the third had chronic atrial fibrillation. Results of this study suggest that an echocardiographic finding of extensive hypertrophy represents a useful marker for detecting patients at increased risk for serious ventricular and atrial arrhythmias.