Ultrasound stethoscopy

In this thesis we repmi the many evaluation studies with the hand-held ultrasound device in the assessment of different cardiac pathologies and in different clinical settings. The reason for using the tetm "ultrasound stethoscopy" is that these devices are augmenting our physical examination by allowing to visualise the heart and hence extend our physical sense of "seeing". Since stethoscopy stands for "seeing the heart" as previously mentioned, the tenn ultrasound stethoscope seems to be the most appropriate term describing these instruments. One could argue that the introduction of echocardiography at the bedside could weaken the importance of auscultation and the physical examination in particular. However, it was echocardiography that brought out the limitations of physical examination in many cardiac conditions and also exposed human auditory limitations (7-10). Although auscultation entered a modem era with the introduction of electronic stethoscopes (11 ), physicians rely on more sophisticated technology. Inadequate training and time pressure due to increasing work load of patients in combination with the availability of advanced technologies are the reasons of poor auscultatory proficiency seen in recently trained physicians particularly in developed countries (12). Nevertheless, we have to admit that direct observation such as seeing is more accurate for cardiac diagnosis than indirect observation such as hearing. "Seeing" enables the preclinical detection of pathologies and especially pathologies that are beyond physical signs, e.g. small mass lesions. The first reactions from experienced echocardiographers to the ultrasound stethoscope were related to its capabilities/limitations and the training required for physicians who use it (13). The last 2 years refinements in the technology of the ultrasound stethoscopes and addition of modalities like spectral Doppler and M-Mode have improved the diagnostic potentials of these devices. No doubt that training is required to use an imaging device. Recently the American Society of Cardiology (14) published guidelines regarding the use of ultrasound stethoscopes recommending Level I of training (15) as an absolute minimal level required. However, recent studies have shown that it is possible to train physicians and students for the detection of significant pathologies in a short period ( 16,17)

Quantification of regional left ventricular function in Q wave and non-Q wave dysfunctional regions by tissue Doppler imaging in patients with ischaemic cardiomyopathy

OBJECTIVE: To quantify regional left ventricular (LV) function and contractile reserve in Q wave and non-Q wave regions in patients with previous myocardial infarction. DESIGN: An observational study. SETTING: Tertiary care centre. PATIENTS: 81 patients with previous myocardial infarction and depressed LV function. INTERVENTIONS: All patients underwent surface ECG at rest and pulsed wave tissue Doppler imaging at rest and during low dose dobutamine infusion. The left ventricle was divided into four major regions (anterior, inferoposterior, septal, and lateral). Severely hypokinetic, akinetic, and dyskinetic regions on two dimensional echocardiography at rest were considered dysfunctional. MAIN OUTCOME MEASURES: Regional myocardial systolic velocity (Vs) at rest and the change in Vs during low dose dobutamine infusion (DeltaVs) in dysfunctional regions with and without Q waves on surface ECG. RESULTS: 220 (69%) regions were dysfunctional; 60 of these regions corresponded to Q waves and 160 were not related to Q waves. Vs and DeltaVs were lower in dysfunctional than in non-dysfunctional regions (mean (SD) Vs 6.2 (1.9) cm/s v 7.1 (1.7) cm/s (p < 0.001), and DeltaVs 1.9 (1.9) cm/s v 2.6 (2.5) cm/s (p = 0.009), respectively). There were no significant differences in Vs and DeltaVs among dysfunctional regions with and without Q waves (Q wave regions: Vs 6.2 (1.8) cm/s, DeltaVs 1.6 (2.2) cm/s; non-Q wave regions: Vs 6.3 (1.9) cm/s, DeltaVs 2.0 (2.0) cm/s). CONCLUSIONS: Quantitative pulsed wave tissue Doppler demonstrated that, among dysfunctional regions, Q waves on the ECG do not indicate more severe dysfunction, and myocardial contractile reserve is comparable in Q wave and non-Q wave dysfunctional myocardium

Clinical utility and cost effectiveness of a personal ultrasound imager for cardiac evaluation during consultation rounds in patients with suspected cardiac disease

OBJECTIVE: To assess the clinical utility and cost effectiveness of a personal ultrasound imager (PUI) during consultation rounds for cardiac evaluation of patients with suspected cardiac disease. METHODS: 107 unselected patients from non-cardiac departments (55% men) were enrolled in the study. After the physical examination the consultant cardiologist performed an echocardiographic study with a PUI. The final report was given instantly to the referring physician. All patients subsequently underwent a study with a standard echocardiographic device (SED). For each patient the consultant cardiologist noted whether the findings of the PUI were adequate for final diagnosis. The total cost when full echocardiography was used was compared with the cost when the PUI was used. The time interval from request to diagnosis was also compared. RESULTS: In 84 (78.5%) patients no further examination with an SED was regarded as necessary. Twenty three patients (21.5%) required a further detailed examination with the SED because of the need for haemodynamic information. There was an excellent agreement for the detection of abnormalities between the two devices (96%). The total cost was euro;132 per patient with the SED and euro;75 per patient with the PUI. According to this study, the use of the PUI can lead to a 33.4% reduction of total cost. The mean time from request to diagnosis at the authors' institutio

Prognostic value of dobutamine-atropine stress myocardial perfusion imaging in patients with diabetes

OBJECTIVE: Exercise tolerance in patients with diabetes is frequently impaired due to noncardiac disease such as claudication and polyneuropathy. This study assesses the prognostic value of dobutamine stress myocardial perfusion imaging in patients with diabetes. RESEARCH DESIGN AND METHODS: A total of 207 consecutive diabetic patients who were unable to undergo exercise stress testing underwent dobutamine-atropine stress myocardial perfusion imaging. Follow-up was successful in 206 of 207 (99.5%) patients. A total of 12 patients underwent early (<60 days) revascularization and were excluded from the analysis. End points during follow-up were hard cardiac events, defined as cardiac death and nonfatal myocardial infarction. RESULTS: Abnormal myocardial perfusion was detected in 125 (64%) patients. During 4.1 +/- 2.4 years of follow-up, 73 (38%) deaths occurred, 36 (49%) of which were due to cardiac causes. Nonfatal myocardial infarction occurred in 7 (4%) patients, and 45 (23%) patients underwent late coronary revascularization. Cardiac death occurred in 2 of 69 (3%) patients with normal myocardial perfusion and in 34 of 125 (27%) patients with perfusion abnormalities (P < 0.0001). A multivariable Cox proportional hazard model demonstrated that, in addition to clinical and stress test data, an abnormal scan had an incremental prognostic value for prediction of cardiac death (hazard ratio 7.2, 95% CI 1.7-30). The summed stress score was an important predictor of cardiac death; the hazard ratio was 1.2 (95% CI 1.07-1.34) per one-unit increment. CONCLUSIONS: Dobutamine-atropine stress myocardial perfusion imaging provides additional prognostic information incremental to clinical data in patients with diabetes who are unable to undergo exercise stress testing

Pulsed wave tissue Doppler imaging for the quantification of contractile reserve in stunned, hibernating, and scarred myocardium

OBJECTIVES: To assess whether quantification of myocardial systolic velocities by pulsed wave tissue Doppler imaging can differentiate between stunned, hibernating, and scarred myocardium. DESIGN: Observational study. SETTING: Tertiary referral centre. PATIENTS: 70 patients with reduced left ventricular function caused by chronic coronary artery disease. METHODS: Pulsed wave tissue Doppler imaging was done close to the mitral annulus at rest and during low dose dobutamine; systolic ejection velocity (Vs) and the difference in Vs between low dose dobutamine and the resting value (DeltaVs) were assessed using a six segment model. Assessment of perfusion (with Tc-99m-tetrofosmin SPECT) and glucose utilisation (by 18F-fluorodeoxyglucose SPECT) was used to classify dysfunctional regions (by resting cross sectional echocardiography) as stunned, hibernating, or scarred. RESULTS: 253 of 420 regions (60%) were dysfunctional. Of these, 132 (52%) were classified as stunned, 25 (10%) as hibernating, and 96 (38%) as scarred. At rest, Vs in stunned, hibernating, and scar tissue was, respectively, 6.3 (1.8), 6.6 (2.2), and 5.5 (1.5) cm/s (p = 0.001 by ANOVA). There was a gradual decline in Vs during low dose dobutamine infusion between stunned, hibernating, and scar tissue (8.3 (2.6) v 7.8 (1.5) v 6.8 (1.9) cm/s, p < 0.001 by ANOVA). DeltaVs was higher in stunned (2.1 (1.9) cm/s) than in hibernating (1.2 (1.4) cm/s, p < 0.05) or scarred regions (1.3 (1.2) cm/s, p = 0.001). CONCLUSIONS: Quantitative tissue Doppler imaging showed a gradual reduction in regional velocities between stunned, hibernating, and scarred myocardium. Dobutamine induced contractile reserve was higher in stunned regions than in hibernating and scarred myocardium, reflecting different severities of myocardial damag

Prognostic value of dobutamine stress echocardiography in patients with diabetes

OBJECTIVE: The aim of this study was to assess the incremental value of dobutamine stress echocardiography (DSE) for the risk stratification of diabetic patients who are unable to perform an adequate exercise stress test. Exercise capacity is frequently impaired in patients with diabetes. The role of pharmacologic stress echocardiography in the risk stratification of diabetic patients has not been well defined. RESEARCH DESIGN AND METHODS: We studied 396 diabetic patients (mean age 61 +/- 11 years, 252 men [64%]) with limited exercise capacity who underwent DSE for evaluation of known or suspected coronary artery disease (CAD). End points were hard cardiac events (cardiac death and non

Improved identification of viable myocardium using second harmonic imaging during dobutamine stress echocardiography

OBJECTIVE: To determine whether, compared with fundamental imaging, second harmonic imaging can improve the accuracy of dobutamine stress echocardiography for identifying viable myocardium, using nuclear imaging as a reference. PATIENTS: 30 patients with chronic left ventricular dysfunction (mean (SD) age, 60 (8) years; 22 men). METHODS: Dobutamine stress echocardiography was carried out in all patients using both fundamental and second harmonic imaging. All patients underwent dual isotope simultaneous acquisition single photon emission computed tomography (DISA-SPECT) with (99m)technetium-tetrofosmin/(18)F-fluorodeoxyglucose on a separate day. Myocardial viability was considered present by dobutamine stress echocardiography when segments with severe dysfunction showed a biphasic sustained improvement or an ischaemic response. Viability criteria on DISA-SPECT were normal or mildly reduced perfusion and metabolism, or perfusion/metabolism mismatch. RESULTS: Using fundamental imaging, 330 segments showed severe dysfunction at baseline; 144 (44%) were considered viable. The agreement between dobutamine stress echocardiography by fundamental imaging and DISA-SPECT was 78%, kappa = 0.56. Using second harmonic imaging, 288 segments showed severe dysfunction; 138 (48%) were viable. The agreement between dobutamine stress echocardiography and DISA-SPECT was significantly better when second harmonic imaging was used (89%, kappa = 0.77, p = 0.001 v fundamental imaging). CONCLUSIONS: Second harmonic imaging applied during dobutamine stress echocardiography increases the agreement with DISA-SPECT for detecting myocardial viability

Relation between left ventricular contractile reserve during low dose dobutamine echocardiography and plasma concentrations of natriuretic peptides

BACKGROUND: In ischaemic cardiomyopathy, raised plasma concentrations of natriuretic peptides are associated with a poor long term prognosis, while the presence of contractile reserve is a favourable sign. OBJECTIVE: To assess the relation between plasma natriuretic peptides and contractile reserve. DESIGN: Prospective observational study. SETTING: Tertiary referral centre. PATIENTS: 66 consecutive patients undergoing low dose dobutamine stress echocardiography to evaluate contractile reserve in regions with contractile dysfunction at rest, divided into two groups: group 1, 31 patients with ischaemic cardiomyopathy (left ventricular ejection fraction < or = 40%) and heart failure symptoms; group 2, 35 patients with normal left ventricular function. MAIN OUTCOME MEASURES: Plasma atrial natriuretic peptide (ANP) and brain natriuretic peptide (BNP), measured using immunoradiometric assays. Contractile reserve was defined as an improvement in segmental wall motion score during infusion of low dose dobutamine. RESULTS: Plasma ANP and BNP concentrations were higher in group 1 than in group 2 (mean (SD): ANP, 17.8 (32.8) v 7.2 (9.7), p < 0.005; BNP, 24.4 (69.0) v 5.0 (14.3) pmol/l, respectively; p < 0.001). In group 1, the presence of contractile reserve was inversely related to ANP and BNP levels; however, patients with contractile reserv

Long term outcome in patients with silent versus symptomatic ischaemia during dobutamine stress echocardiography

OBJECTIVES: To compare the long term prognosis of patients having silent versus symptomatic ischaemia during dobutamine stress echocardiography (DSE). DESIGN: Observational study. SETTING: Tertiary referral centre. PATIENTS: 931 patients who experienced stress induced myocardial ischaemia during DSE. RESULTS: Silent ischaemia was present in 643 of 931 patients (69%). The number of dysfunctional segments at rest (mean (SD) 9.6 (5.1) v 8.8 (5.0), p = 0.1) and of ischaemic segments (3.5 (2.2) v 3.8 (2.1), p = 0.2) was comparable in both groups. During a mean (SD) follow up of 5.5 (3.3) years, there were 169 (18%) cardiac deaths and 86 (9%) non-fatal infarctions. Multivariable Cox regression analysis showed age (hazard ratio (HR) 1.1, 95% confidence interval (CI) 1.02 to 1.05), previous myocardial infarction (HR 1.4, 95% CI 1.1 to 2.0), and number of ischaemic segments during the test (HR 2.0, 95% CI 1.0 to 3.7) as independent predictors of cardiac death and myocardial infarction. For every additional ischaemic segment there was a twofold increment in risk of late cardiac events. The annual cardiac death or myocardial infarction rate was 3.0% in patients with symptomatic ischaemia and 4.6% in patients with silent ischaemia (p < 0.01). Silent induced ischaemia was an independent predictor of cardiac death and myocardial infarction (HR 1.7, 95% CI 1.1 to 2.0). During follow up symptomatic patients were treated more often with cardioprotective therapy (p < 0.01) and coronary revascularisation (145 of 288 (50%) v 174 of 643 (27%), p < 0.001). CONCLUSIONS: Patients with silent ischaemia had a similar extent of myocardial ischaemia during DSE compared to patients with symptomatic ischaemia but received less cardioprotective treatment and coronary revascularisation and experienced a higher cardiac event rate