The left ventricle’s (LV) pressure-volume (P-V) loop visually represents an important relationship between the chamber’s pressure and volume over a single cardiac cycle. In the following diagram, systole is red, and diastole is blue. The P-V loop consists of four events:
Intraabdominal hypertension (IAH) and abdominal compartment syndrome are defined as sustained intraabdominal pressure (IAP) ≥ 12 mmHg and > 20 mmHg with new organ dysfunction, respectively. This can be challenging to diagnose in patients who are pregnant, obese, or with ascites. Bladder pressure from a Foley catheter can be used…
Point-of-care ultrasound (POCUS) can be extremely helpful during advanced cardiovascular life support (ACLS) with ongoing chest compressions and resuscitation. POCUS can help rule in or out certain etiologies (the H’s and T’s) for why a patient arrested. During the pulse check, I record the clearest subcostal 4 or 5 chamber…
The right ventricle (RV) is designed to be a compliant volume chamber that pumps against a low-pressure, low-resistance pulmonary arterial (PA) system. RV-PA coupling refers to the proportional alignment between RV contractility and afterload. In situations of increased RV afterload like pulmonary hypertension, the RV can adapt (e.g., anatomic remodeling…
Carotid body tumors are vascular tumors arising from the carotid body’s paraganglion cells at the bifurcation of the internal and external carotid arteries (ICA and ECA, respectively). The Shamblin classification is used to categorize these tumors based on their involvement with adjacent structures, namely the ICA, ECA, common carotid artery…
Around this time last year, I wrote a post outlining my 2022 productivity workstation. Since then, I’ve made significant changes, including the desk, monitors, and peripherals. I utilize every item listed for tasks ranging from content creation, media consumption, programming, video conferencing, and general-purpose computing. Here’s an outline of what…
The Doppler shift equation describes the observed change in frequency or wavelength of a wave (such as sound, light, or radio waves) when the source of the wave and the observer are in relative motion. This phenomenon is known as the Doppler effect and is incredibly important to understand when…
Cardiac output (CO) is mathematically calculated as the product of heart rate and stroke volume. It’s related to preload, afterload, and contractility. One echocardiographic technique I routinely use to estimate a patient’s stroke volume is the volume-time integral (VTI). The VTI method is based on the Doppler effect which relates…
Mitral annular calcification (MAC) is a degenerative process that affects the fibrous ring around the mitral valve. It is thought to be caused by chronic inflammation, oxidative stress, and altered calcium metabolism. Although often asymptomatic, MAC can cause mitral valve stenosis and/or regurgitation, with associated symptoms ranging from shortness of…
Physician-modified endovascular grafts (PMEGs) offer a percutaneous and effective option for repairing complex thoracoabdominal aortic aneurysms. A stent graft is modified onsite using strict sterile technique with reinforced fenestrations created based on the patient’s specific anatomy. Additionally, radiopaque markers are added to help with stent graft alignment in vivo. In…