The Integration of Doppler Ultrasound With Two-Dimensional Echocardiography and the Noninvasive Cardiac Hemodynamic Revolution of the 1980s

Complete dislodgement of a mechanical valve prosthesis: A rare but potentially life-threatening event: a case report

RATIONALE

Complete dislodgement of a mechanical valve is extremely uncommon as a long-term issue after getting a substitute mitral valve, and this report details an incident of complete detachment of a mechanical valve.

PATIENT CONCERNS

A 50-year-old woman, who underwent mitral mechanical valve replacement 2 decades earlier at another facility, was urgently admitted due to sudden cardiogenic shock.

DIAGNOSES

Transthoracic echocardiograms revealed severe malfunction of the mitral valve prosthesis, characterized by significant mitral regurgitation and moderate pulmonary hypertension. Following the insertion of extracorporeal membrane oxygenation and an intra-aortic balloon pump, the hemodynamics stabilized. Coronary angiography displayed the prosthetic mitral valve ring and leaflet floating in the left atrium, as confirmed by preoperative real-time 3-dimensional transesophageal echocardiography. A complete separation of the prosthetic ring and leaflet from the suture ring was observed.

INTERVENTIONS

The patient promptly underwent bioprosthetic mitral valve replacement.

OUTCOMES

The patient's postoperative course was uneventful, leading to discharge in good condition.

LESSONS

A crucial aspect is comprehending the structure of the prosthetic valve itself. The use of transthoracic echocardiography and real-time 3-dimensional transesophageal echocardiography provides additional structural and functional details, enhancing support for potential life-saving interventions. Echocardiography plays a significant role in evaluating the morphology and function of prosthetic valves.

Using Quality Improvement Methodology to Standardize Doppler Acquisition in a Pediatric Cardiology Echocardiography Laboratory

In echocardiography, the Doppler principle allows the measurement of tissue velocities. Using the Bernoulli equation, velocities are translated to estimated pressure differences, which dictate the timing of cardiac interventions. Our echocardiography laboratory demonstrated variability in the Doppler interrogation of heart valves, leading to difficulties in comparison over time and study accuracy. To align with previously published quality metrics in echocardiography, our laboratory used quality improvement methodology to achieve measurable improvement in Doppler acquisition.

Methods

We developed a standardized protocol for Doppler acquisition and translated it to a 20-point scoring system. We established a baseline over 4 months via random assessment of 2 first-time, normal studies per day. Interventions included standardizing the process for acquisition, education, visual tracking, and individual feedback.

Results

The percentage of studies with a score of 16 or higher preintervention was 17%. The median score was 13.4. In total, we analyzed 407 studies, 173 pre- and 234 postintervention. Over a 4-month intervention period, the median score improved to 18.1, with 85% of studies achieving a score of 16 or higher. Special cause variation occurred after protocol distribution, education, and feedback.

Conclusions

Our initiative demonstrated significant improvement in the Doppler interrogation of cardiac structures using a measurable scoring system and a concrete goal of incorporating 20 areas of Doppler assessment in normal studies. Our next step is to spread this assessment to abnormal studies, thus developing consistency in evaluating all studies throughout the laboratory.

Two Barricades in a Row Mixed Lesion of Dynamic Left Ventricular Outflow Tract Obstruction and Aortic Stenosis: Finding the Culprit for Decision Making

Concurrent lesions of dynamic left ventricular outflow tract obstruction (DLVOTO) with aortic stenosis pose a challenge in the measurement of the pressure gradient and severity of each lesion. Determining the true culprit lesion is difficult and challenging. The establishment of true culprit lesion is crucial in deciding the future course of action. We present two cases of concurrent DLVOTO and aortic stenosis. Although the composition of lesions is similar, the severity of each lesion was different and described a variety of technical problems. Finding the culprit through the shape of the stenotic jet from the continuous wave Doppler as well as other different technical approaches is the critical point of this case report. The first patient showed nonsignificant DLVOTO with severe aortic stenosis in which transthoracic echocardiography (TTE) alone was sufficient to find the culprit. Meanwhile, the second patient concluded to have significant DLVOTO with moderate aortic stenosis based on TTE and transesophageal echocardiography examination data. Jet morphology from Doppler examination is a crucial finding to differentiate DLVOTO with aortic stenosis, along with other parameters that might help find the dominant lesion. Multiple modalities with several tailor-made technical considerations might be needed to establish a culprit lesion.