ACC/AHA/ASE 2003 guideline update for the clinical application of echocardiography: summary article: a report of the American College of Cardiology/American Heart Association Task Force on Practice Guidelines (ACC/AHA/ASE Committee to Update the 1997 Guidelines for the Clinical Application of Echocardiography)

Primary left atrial angiosarcoma mimicking severe mitral valve stenosis

Primary cardiac tumours are quite rare and most of these tumours are benign. In this report, a patient presented with heart failure symptoms attributable to severe mitral valve stenosis. Echocardiography showed a dense left atrial mass causing functional mitral valve obstruction. The morphological and intraoperative presentation was highly suggestive of a myxoma but histopathological examination found a primary pedunculated cardiac angiosarcoma. The role of two dimensional and transoesophageal echocardiography in the assessment of cardiac masses and tumours is discussed.

Relevance of tissue Doppler in the quantification of stress echocardiography for the detection of myocardial ischemia in clinical practice

In the present article we review the main published data on the application of Tissue Doppler Imaging (TDI) to stress echocardiography for the detection of myocardial ischemia. TDI has been applied to stress echocardiography in order to overcome the limitations of visual analysis for myocardial ischemia. The introduction of a new technology for clinical routine use should pass through the different phases of scientific assessment from feasibility studies to large multicenter studies, from efficacy to effectiveness studies. Nonetheless the pro-technology bias plays a major role in medicine and expensive and sophisticated techniques are accepted before their real usefulness and incremental value to the available ones is assessed. Apparently, TDI is not exempted by this approach : its applications are not substantiated by strong and sound results. Nonetheless, conventional stress echocardiography for myocardial ischemia detection is heavily criticized on the basis of its subjectivity. Stress echocardiography has a long lasting history and the evidence collected over 20 years positioned it as an established tool for the detection and prognostication of coronary artery disease. The quantitative assessment of myocardial ischemia remains a scientific challenge and a clinical goal but time has not come for these newer ultrasonographic techniques which should be restricted to research laboratories.

Cardiac findings during uncomplicated acute influenza in ambulatory adults

BACKGROUND

Previous studies have reported abnormal cardiac findings in up to 43% of ambulatory adults with influenza. This study was conducted to determine the frequency, magnitude, and duration of myocardial dysfunction in such persons.

METHODS

We enrolled 30 previously healthy young adults without known cardiovascular disease who presented to the clinic <or=72 h after onset of influenza symptoms and had a positive influenza antigen test. Most patients received antiviral therapy, and all underwent serial electrocardiography and had blood specimens collected on days 1, 4, 11, and 28 after presentation for measurement of total creatine kinase (CK) level, CK isoenzyme MB (CK-MB) level, troponin I level, and selected cytokine levels. Echocardiography was performed on days 4, 11, and 28.

RESULTS

None of the patients had an elevated CK-MB index or troponin I level. Abnormal electrocardiogram findings were noted in 53%, 33%, 27%, and 23% of patients on days 1, 4, 11, and 28, respectively, but none of the findings were considered to be clinically significant. No patient had significant changes in the ejection fraction or abnormal wall motions.

CONCLUSIONS

Most ambulatory young adults with acute influenza have clinically insignificant abnormal electrocardiogram findings early during the illness. These abnormalities resolve promptly and are not associated with changes in cardiac markers or echocardiogram findings.

The Use of 3D Epiaortic Scanning to Enhance Evaluation of Atherosclerotic Plaque in the Ascending Aorta: A Case Series

Transesophageal echocardiography (TEE) is becoming the standard of practice for cardiopulmonary bypass (CPB) surgery. Unfortunately, large sections of the ascending aorta are not visible on TEE, and epiaortic scanning has proven superior to TEE and aortic palpation in determining the extent of plaque in the ascending aorta. The recently introduced x4 3-dimensional (3D) ultrasound probe allows both real time 3D imaging and gated acquisition sequences. We present a case series in which 3D ultrasound was used for epiaortic imaging in patients undergoing elective cardiac surgery, and we discuss the benefits and limitations of this imaging modality.

Bedside limited echocardiography by the emergency physician is accurate during evaluation of the critically ill patient

OBJECTIVE

Echocardiography can be a rapid, noninvasive, objective tool in the assessment of ventricular function and preload during resuscitation of a critically ill or injured child. We sought to determine the accuracy of bedside limited echocardiography by the emergency physician (BLEEP) in estimation of (1) left ventricular function (LVF) and (2) inferior vena cava (IVC) volume, as an indirect measure of preload.

METHODS

We conducted a prospective observational study of a convenience sample of patients who were admitted to our intensive care unit. All patients underwent BLEEP followed by an independent formal echocardiogram by an experienced pediatric echocardiography provider (PEP). IVC volume was assessed by measurement of the maximal diameter of the IVC. LVF was determined by calculating shortening fraction (SF) using M-mode measurements on the parasternal short-axis view at the level of the papillary muscle. An independent blinded pediatric cardiologist reviewed all images for accuracy and quality. Estimates of SF obtained on the BLEEP examination were compared with those obtained by the PEP.

RESULTS

Thirty-one patients were enrolled. The mean age was 5.1 years (range: 23 days-16 years); 48.4% (15 of 31) were girls; 58.1% (18 of 31) were on mechanical ventilatory support at the time of their study. There was good agreement between the emergency physician (EP) and the PEP for estimation of SF (r = 0.78). The mean difference in the estimate of SF between the providers was 4.4% (95% confidence interval: 1.6%-7.2%). This difference in estimate of SF was statistically significant. Similarly, there was good agreement between the EP and the PEP for estimation of IVC volume (r = 0.8). The mean difference in the estimate of IVC diameter by the PEP and the EP was 0.068 mm (95% confidence interval: -0.16 to 0.025 mm). This difference was not statistically significant.

CONCLUSIONS

Our study suggests that PEP sonographers are capable of obtaining images that permit accurate assessment of LVF and IVC volume. BLEEP can be performed with focused training and oversight by a pediatric cardiologist.

Comparison of image quality between a narrow caliber transesophageal echocardiographic probe and the standard size probe during intraoperative evaluation

BACKGROUND

Transesophageal echocardiography (TEE) has become an integral part of the evaluation and monitoring of patients during cardiac operation. Until recently, the smallest TEE probe with multiplane imaging measured 13 mm in diameter. This size is now standard for adult TEE probes. Recently, a new TEE probe has become available (MiniMulti TEE probe, Philips Medical Systems, Andover, Mass), which has a diameter of 8 mm. Although using a smaller probe is attractive, the quality of images it generates when used in adults has not yet been examined.

OBJECTIVE

The purpose of this study was to compare TEE studies done with both probes.

METHODS

After informed consent was obtained, full intraoperative TEE studies were performed in 20 patients with a small pediatric probe. The study was then repeated using a standard adult probe. The studies were read in random order by two experienced echocardiographers blinded to probe used. For each study, 18 anatomic cardiac structures and 5 Doppler patterns were subjectively graded as excellent (1), good (2), fair (3), or poor (4) in quality. The average score for each structure or Doppler profile was computed for each probe.

RESULTS

The average score for all findings was lower (better) for the adult TEE probe (1.4 +/- 0.4 vs 1.7 +/- 0.4; P =.003). When each finding was compared separately, several cardiac structures (left ventricle [LV], pericardium, right ventricle [RV], interatrial septum, left atrium, left atrial appendage, mitral valve, aortic valve) had better scores with the adult probe, and the differences for the LV and RV were larger than those for the other findings (LV scores differed by 0.7, P =.0004; RV scores differed by 0.5, P =.01). There was no significant difference between probes when evaluating venous structures (coronary sinus, superior vena cava, pulmonary vein), the thoracic aorta, or the right atrium or tricuspid valve. In addition, Doppler patterns were not significantly different with the two probes. There were two findings that were missed with the small probe and seen with the adult probe (one aortic plaque and one left atrial appendage thrombus).

CONCLUSIONS

In the adult, the larger probe provides better images, particularly of the RV and LV. In addition, important findings may be missed with the smaller probe. However, if the adult probe cannot be passed, the pediatric probe is a reasonable alternative.

Intraoperative ultrasound

Intraoperative ultrasound (IOUS) can provide various diagnostic information that is otherwise not available, and can guide or assist various surgical procedures in real time. With refinement of equipment, IOUS is currently used in a wide variety of surgical operations,such as hepatobiliary, pancreatic, endocrine, cardiovascular,and neurologic surgery. Our overview of IOUS, including instrumentation,techniques, indications, advantages, disadvantages,and future perspective, is described in this article. Being safe, quick, accurate, and versatile intraoperatively, IOUS is a valuable technique that surgeons are recommended to master to improve intraoperative decision making and surgical procedures.

Screening, early detection, and diagnosis of pulmonary arterial hypertension: ACCP evidence-based clinical practice guidelines

Pulmonary arterial hypertension (PAH) occurs as an idiopathic process or as a component of a variety of disease processes, including chronic thromboembolic disease, connective tissue diseases, congenital heart disease, and exposure to exogenous factors including appetite suppressants or infectious agents such as HIV. This article reviews evidence for screening in susceptible patient groups and the approach to diagnosing PAH when it is suspected, and provides specific recommendations for applying this evidence to clinical practice.

Effect of electrical stimulus parameters on the development and propagation of action potentials in short excitable fibres

Intracellular action potentials (IAPs) produced by short fibres in response to their electrical stimulation were analysed. IAPs were calculated on the basis of the Hodgkin-Huxley (1952) model by the method described by Joyner et al. (1978). Principal differences were found in processes of activation of short (semilength L less than 5 lambda) and long fibres under near-threshold stimulation. The shorter the fibre, the lower was the threshold value (Ithr). Dependence of the latency on the stimulus strength (Ist) was substantially non-linear and was affected by the fibre length. Both fibre length and stimulus strength influenced the IAP amplitude, the instantaneous propagation velocity (IPV) and the site of the first origin of the IAP (and, consequently, excitability of the short fibre membrane). With L less than or equal to 2 lambda and Ithr less than or equal to Ist less than or equal to 1.1Ithr, IPV could reach either very high values (so that all the fibre membrane fired practically simultaneously) or even negative values. The latter corresponded to the first origin of the propagated IAP, not at the site of stimulation but at the fibre termination or at a midpoint. The characters of all the above dependencies were unchanged irrespective of the manner of approaching threshold (variation of stimulus duration or its strength). Reasons for differences in processes of activation of short and long fibres are discussed in terms of electrical load and latency. Applications of the results to explain an increased jitter, velocity recovery function and velocity-diameter relationship are also discussed.