Tag Archives: Cardiac

Inferior vena cava in severe tricuspid regurgitation

Here are spectacular images of massively dilated inferior vena cava and hepatic veins in a patient with severe tricuspid regurgitation shared by Dr. Robert Jones.

Below is a related case where patient had ‘pulsatile’ inferior vena cava from severe tricuspid regurgitation. Note the hepatic-vein IVC confluence and its’ entry into right atrium suggesting the pulsatile vessel is not the aorta. Can be difficult to distinguish in suboptimal images, where pulsed wave Doppler demonstration of arterial vs venous waveforms will help. The etiology of tricuspid regurgitation in this case was valve destruction due to endocarditis. Reference: Patel KD, et al. CASE (Phila). 2017.

Valvular vegetations

Though transesophageal echocardiography is required in most patients suspected to have infective endocarditis because of better sensitivity, valvular vegetations can be seen on a transthoracic echocardiogram, especially when large. It is important for nephrologists to be aware of the characteristic features of these lesions as we frequently take care of patients with dialysis access infection and bacteremia. Essentially, vegetation is an infected mass usually attached to cardiac valves or implanted intracardiac materials such as pacemaker wires. Vegetations tend to be irregular in shape, mobile but attached to the upstream (= low-pressure) side of the valve. Fresh vegetations are usually hypoechoic or isoechoic to the myocardium whereas old lesions tend to be hyperechoic, and may be calcified. Valvular regurgitation due to destructive valve lesions is a frequent accompaniment and hence Color Doppler evaluation should always be performed. Following are two classic examples (grey scale)

Pericardial versus pleural effusion on PLAX view

We may find both pericardial and pleural effusions in the parasternal long axis (PLAX) view and mistaking one for the other can lead to inappropriate management. The descending thoracic aorta is the anatomical landmark to differentiate between these two effusions. Fluid anterior to the descending aorta (toward the top of the screen) is pericardial effusion and the fluid at or posterior is likely pleural effusion. Here is a cross section of thorax demonstrating the relationship of the descending aorta to the left lung and pleura.

Here are two sonographic images illustrating this concept.

Below is an example of left pleural effusion in a patient with malignancy that can be easily confused with pericardial effusion on quick beside exams. Pay attention to the location of descending aorta. Scanning in different views helps further. Also note fibrin stranding in the mid-axillary view suggestive of exudative pleural effusion.

Other views of the heart

Please refer to ‘Focus on POCUN‘ series on the Renal Fellow Network for brief notes on other echocardiographic windows.

Here is my video talking about basic elements of FoCUS.

PLAX view: Orientation

The parasternal long axis view or the PLAX is obtained by placing the transducer to the left of the sternum in 3rd or 4th intercostal space with the orientation marker toward patient’s right shoulder or 10 o’ clock position, which is essentially the ‘long axis’ of the heart. For better understanding of the procedure, watch my video 3 (~19:33) and video 8 (~5:22).

The following figures demonstrate the plane in which we are slicing the heart to obtain PLAX view.

PLAX plane
Orientation to the PLAX view in lying down position

Normal sonographic anatomy of the PLAX view:

In a technically ‘good’ PLAX view, both the mitral valve and the aortic valve will be clearly seen and will be roughly in the center of the image, stacked on top of each other. The base of the left ventricle (LV), but not the apex, will be visible. The right ventricular outflow tract (RVOT) will be seen on the top of the image. Note that the right ventricle has noticeably thinner and smaller walls compared to the LV. The right atrium (RA) is not visible in this view. On the right, the left atrium (LA), aorta and RVOT each should roughly take up one-third of the image. Pericardium appears as a bright border and the descending thoracic aorta is visible at the bottom of the image, as a circle outside the LA.

Focus on FoCUS: The 4 basic views of the heart

FoCUS = Focused Cardiac Ultrasound

FoCUS consists of 4 basic views of the heart namely parasternal long- and short-axis views, the apical 4-chamber view, and the subxiphoid view, as described in the Rapid Ultrasound in Shock (RUSH) protocol.

The parasternal views are obtained with the probe positioned just left of the sternum at intercostal space 3 or 4. It’s like slicing the heart in ‘its’ sagittal and transverse planes respectively.

The long axis of the heart is oblique to that of the body, extending from right shoulder to the left hip

The apical 4-chamber view of the heart is obtained by placing the probe just below the nipple line at the point of maximal impulse of the heart. It’s like slicing the heart in its coronal plane.

The subxiphoid 4-chamber view is obtained with the probe aimed up toward the left shoulder from a position just below the subxiphoid tip of the sternum. The image is similar to that of Apical 4C except that it is slightly tilted to the right. It is easier to obtain than the apical 4C and helps to assess pericardial effusion quickly. Note that you’ll see the liver on top of the image as we are using it as a window to look at the heart.

It is important to have an idea of all these 4 views of the heart, as some views may not be well visualized depending on the individual patient’s body habitus and position, necessitating an alternative approach.