left ventricle

So think about what happens with standing, dehydration, exercise, or anything that decreases preload.

The LV cavity gets smaller, the septum and mitral valve come closer together, and the obstruction can become more severe.

On the other hand, increasing preload and reducing excessive contractility can reduce the obstruction.

That physiology explains many of the classic bedside findings.

The diagnosis is primarily based on cardiac imaging in the appropriate clinical context.

Echocardiography is usually the first line test.

We are looking at left ventricular wall thickness, ventricular geometry, systolic and diastolic function, mitral valve anatomy, systolic anterior motion, and especially the presence and severity of LV outflow tract obstruction.

In adults, unexplained maximal LV wall thickness of 15 mm or greater generally establishes the morphologic phenotype of HCM when other causes of hypertrophy have been excluded.

And the third question, surgical or percutaneous?

Surgical means through the chest, a centromag supporting the right heart and another supporting the left, or a long-term HeartMate 3 LVAD.

Percutaneous means the Protec Duo, a temporary right ventricular assist device, and the impeller, temporary and able to support either side depending on the model.

We'll take the Protec Duo where it belongs, with right heart failure, and give the impeller its own section at the end.

Another common use of impellas is as a left ventricular vent in patients who are on veno-arterial ECMO, which the combination of the two is also called ECPELLA.

The nice thing about that configuration is that the impella offloads the left ventricle to promote recovery, but can also support the LV as part of a de-escalation for Mecmo.

Some centers are pretty aggressive about using Impella intraoperatively for high-risk cardiac surgery to aid in separation from cardiopulmonary bypass and to minimize the vasoactive support that the patient needs in the early postoperative period.

Finally, many ICUs at transplant centers will take care of patients with chronic heart failure who have an Impella in place to achieve a higher priority on the transplant list waiting a heart transplant.

Back to the patient.

Despite several attempts to wean him off the impella, he continues to require a pretty significant support.

His LV is failing.

Farther Workup has revealed that he is unfortunately not a candidate for heart transplant.

And so your preload is the filling of the ventricles.

Don't forget, you have RV preload and LV preload, right? So your RV preload is determined by your venous return.

I mean, we're going to talk about structurally normal hearts here, right? Yep.

Yep.

So in a structurally normal heart, your venous return comes back to that right side.

If you have decreased venous return, you'll have decreased RV preload, which is then subsequently everything else decreased preload.

Then if you look at your LV preload, your LV preload is determined by the blood returning from the pulmonary veins.

into the left side of the heart so you need to have adequate return on both sides to have adequate preload