Month: August 2023

A 77-year-old patient presented to a rural Emergency Department with a chief complaint of shortness of breath a day prior to presentation. Patient also reported that he fell several weeks ago and hurt his ribs. He was subsequently admitted to the hospital and was ultimately treated for pyelonephritis. He endorsed being more sedentary than usual for the next several weeks. On the day of presentation he was lying in bed when he began to suddenly feel short of breath. He denied feeling any chest pain, lightheadedness, dizziness, nausea, vomiting, diarrhea, diaphoresis, jaw or arm pain. His shortness of breath had self resolved prior to coming into the emergency department. On physical examination, the patient was alert and had mild respiratory distress. He was tachycardic and also found to have inspiratory crackles in the right lower lung fields. The remainder of the physical exam was within normal limits.

Upon arrival, vitals were as follows:

BP: 92/70 | HR: 118 | RR: 18 | T: 98.2 | Sp02: 80’s% on RA to 90% with 15L NRB

Point of care ultrasound was performed and the following images were obtained. In these images, what do you notice and how does this change your patient management?

View shown in the image above is the parasternal short axis. To perform this technique, use the phased array transducer and place it around the 4th intercostal space, next to the sternum, with the probe marker to the patient’s right shoulder. For example:

Clockwise rotation of the probe (90 degrees) where the indicator is pointing towards the patient's left shoulder will provide a short axis view of the left ventricle. Normal parasternal short axis view in a patient without cardiac dysfunction will include the right ventricle sitting as a semi-circle on top of the circular left ventricle. For example: 

In our case, the right ventricle is pushing down on the left ventricle, indicating increased right sided pressures. This is the classic “D-sign” of the left ventricle, the septum has become straight due to the right sided pressures. 

Classically, the apical four view is used to diagnose elevated right sided pressures by comparing chamber sizes. However, this view can be challenging at times. In our case, we show the effectiveness of diagnosing right sided pressures using a parasternal short axis view [Figure 3].

Discussion 

We typically observe indications of increased pressures in the pulmonary artery and strain on the right side of the heart. These indications can be identified through the presence of reduced movement in the right ventricular wall, enlargement of the right ventricle and right atrium, abnormal motion of the septum during systole, and a dilated inferior vena cava that does not collapse during respiration.

In our case, POCUS utilizing the parasternal short axis view of the heart indicated the “D-sign”. In a normal heart with proper physiological functioning, the pressure in the left ventricle is higher than the pressure in the right ventricle. As a result, during systole the left ventricle maintains a round shape, causing the intraventricular septum to bulge into the right ventricle. However, if the right ventricle pressures are elevated, the septum becomes straight, changing the shape of the left ventricle into a "D".

 Case Conclusion

Visualization of the D sign led to a high concern for pulmonary embolism. Management of the patient’s hypotension was transitioned from fluid resuscitation to vasopressors, on which he was stabilized. He was then taken for a STAT CTA, showing a large saddle pulmonary embolus. The patient was treated with thrombolytics, and he was transferred to a tertiary care center for higher level of care. There, the patient underwent thrombectomy with removal of significant clot burden as below:

His clinical status continued to improve and he was discharged on hospital day 7 with no residual complications. 

In this case, recognition of the D-sign allowed for prompt and effective management of a critically ill patient, and the patient made a full recovery. Key clinical advantages were expediting a difficult diagnosis in a patient who was reportedly asymptomatic at the time of presentation, a rapid transition from fluid resuscitation (which could have worsened his right heart strain) to vasopressor support, and early imaging and thrombolytics before his clinical picture could worsen.