Echocardiography of the Right Side of the Heart

Indications for echocardiography and confirmation rates of cardiovascular diseases: experience of a specialist cardiac outpatient clinic in Kumasi, Ghana

Background

Transthoracic echocardiography is a very helpful noninvasive cardiovascular imaging technique for the diagnosis and risk stratification in the management of patients with cardiovascular diseases. We aimed to review the clinical indications for transthoracic echocardiography and the confirmation rate of cardiovascular diseases by echocardiography at a specialist cardiac clinic in Ghana.

Methods

Using a cross-sectional study design, the echocardiography reports of all patients above the age of 15 who were assessed at the clinic were analyzed. Data on patient demographics, clinical history, clinical indication for echocardiography, and the echocardiographic findings were analyzed using version 25.0 of the Statistical Package for Social Sciences (SPSS).

Results

A total of 594 participants were studied. The age range of participants was 15-96 years, with a mean (± standard deviation) age of 53.72 (± 17.25) years. There were more females (50.17%) than males (49.83%). Most (54.21%) of the participants had echocardiography for cardiac evaluation. Other indications included hypertension/hypertensive heart disease (HHD) (n = 131; 22.06%), heart failure (n = 69; 11.62%), chest pains (n = 12; 2.02%), and valvular heart disease (VHD) (n = 11; 1.85%). Three hundred and eight-nine (70.30%) of the participants had their clinical diagnoses confirmed by echocardiography; echocardiographic confirmation rates for heart failure, VHD, and HHD were 92.75%, 90.91%, and 88.54%, respectively.

Conclusion

Echocardiography showed high confirmation rates for our patients with heart failure, VHD, and HHD. Prompt usage of this noninvasive cardiovascular imaging for the initial evaluation of patients with cardiovascular diseases is highly recommended.

Hemodynamic Consequences of Heart-Lung Interactions

The management of critically ill patients requires a fundamental understanding of cardiopulmonary interactions associated with mechanical ventilation. The hemodynamic changes due to ventilation are a result of changes in lung volume and intrathoracic pressure (ITP) and can occur during spontaneous or positive pressure ventilation despite constant tidal volumes. Pulmonary vascular resistance (PVR) and mechanical heart-lung interactions play prominent roles in determining the hemodynamic response to mechanical ventilation. Lung inflation alters PVR and right ventricular wall tension and, at high lung volume, mechanically limits cardiac volumes. The authors will consider the mechanisms of the effects of ITP on the pulmonary arterial and venous branches. These effects will aid in understanding the complex interactions between ventilation and right and left ventricular pressures and volumes, as well as the influence of lung inflation pressure on ventricular interdependence.

Association between cardiothoracic ratio, left ventricular size and systolic function in patients undergoing computed tomography coronary angiography

The present study aimed to investigate the association between cardiothoracic ratio (CTR) and left ventricular (LV) systolic function parameters in patients with or without preserved LV ejection fraction (LVEF). A total of 203 subjects suspected with coronary artery disease underwent chest radiography and dual source computed tomography coronary angiography (DSCT-CA). The LV systolic function parameters: LV end-diastolic volume index (LVEDVI), LV end-systolic volume index (LVESVI), and LVEF were measured from the DSCT-CA. The association between CTR and LV systolic function parameters was analyzed according to LVEF value (<55%, depressed LVEF group; versus ≥55%, preserved LVEF group) and CTR value (<0.5, normal range CTR group; versus ≥0.5, larger CTR group). The LVEDVI and LVESVI were higher in the depressed LVEF group compared with the preserved LVEF group (108.56±57.15 vs. 67.52±14.56 ml/m², P<0.001; and 64.07±37.81 vs. 20.23±7.23 ml/m², P<0.001, respectively) and lower in the normal range CTR group compared with the larger CTR group (67.10±15.00 vs. 77.30±34.32 ml/m², P=0.009 and 21.94±8.96 vs. 28.97±26.54 ml/m², P=0.017, respectively). Significant correlations were found between CTR and LVEDVI, and LVESVI and LVEF in the depressed LVEF group (r=0.66, P<0.001; r=0.65, P<0.001; and r=−0.46, P=0.018, respectively). However, there was no significant association detected between CTR and LV systolic function parameters in the other subgroups. The LVEDVI and LVESVI showed an inverse correlation with the LVEF in each group. Although the CTR was not a reliable indicator of LV size and systolic function in patients with preserved LVEF, it was correlated with LV size and LVEF in patients with depressed LVEF.

The Use of Echocardiography in the Intensive Care Unit

Echocardiography is a powerful diagnostic tool that has become an indispensable part of intensive care medi cine. There is a broad clinical application for the noninva sive real-time structural and functional assessment of the critically ill patient. The echocardiograph provides on-line visual information and software for data manipu lation at the intensive care bedside without significant discomfort or risk. Assessment of ventricular function, hemodynamics, pericardial pathology, valvular status, and the outcomes of cardiac surgical interventions are naturally suited to this modality. Transesophageal echo cardiography is an important adjunct to the standard transthoracic examination, particularly in those pa tients with inadequate precordial images. Anatomic, physiologic, and hemodynamic findings can be corre lated in a variety of clinical conditions to make and confirm diagnoses and to direct management in a manner complementary to routine intensive care. Indi cations for echocardiography in the intensive care unit at this institution included assessment of ventricular function, valvular function, endocarditis, complications of surgery, abnormal hemodynamics, evaluation of intra cardiac source of embolus, and echocardiographic- guided endomyocardial biopsy. In this review, the tech niques, indications, and clinical applications of transthoracic and transesophageal echocardiography in the intensive care setting are explored, with a focus on experience in the cardiac surgical patient.