Cardiology & Hemodynamics study guide previews.

The balance between venous return and right ventricular (RV) function. CVP is not a direct measure of volume status - it must be interpreted in clinical context. Tip should lie in the lower superior vena cava or right atrium. Zero transducer at the phlebostatic axis include th intercostal space, mid-axillary line (approximates the right atrium), Supine position preferred (head of bed ≤30), and Read CVP at end-expiration to minimize respiratory variation.

Heart Failure Basics: Overview, Causes, Diagnosis, Management, Prognosis, More introduces the clinical pattern, physiology, and bedside decisions that matter for emergency and critical care practice.

Heart Failure (HF) is a clinical syndrome in which the heart is unable to pump sufficient blood to meet the body’s metabolic needs, due to either impaired ventricular filling (diastolic dysfunction) or impaired ejection of blood (systolic dysfunction).

Prevalence include million adults in the U.S and Incidence increases with age; >10% in people >70 years old. Hospitalizations include Leading cause of hospitalization in people over 65. Prognosis include year mortality is ~50% after diagnosis and Frequent readmissions (especially within 30 days of discharge). Heart failure results from structural or functional cardiac disorders that impair ventricular filling or ejection. In response to decreased cardiac output include SNS activation leading to increased heart rate and contractility, RAAS activation leading to vasoconstriction, fluid retention, ADH secretion leading to water retention, and BNP/ANP release** leading to counter-regulatory (vasodilation, natriuresis).

ECG Recognition & Clinical Approach - Whiteboard Medicine. Posterior ST-elevation myocardial infarction (Posterior STEMI) is a form of acute coronary occlusion involving the posterior wall of the left ventricle-most commonly supplied by the left circumflex artery (or occasionally the RCA with a dominant PDA). Key challenge include The standard 12-lead ECG does NOT directly visualize the posterior myocardium and Why the 12-Lead ECG Misses Posterior MI. Result includes instead of ST elevations, posterior infarction produces reciprocal changes in anterior leads.

Normal STEMI include ST elevation seen directly over infarcted myocardium. ST elevation exists - but it faces away from recording electrodes.

A pulmonary artery catheter (PAC) is a multi-lumen, flow-directed catheter advanced from a central vein through the right heart into a branch of the pulmonary artery. With a small balloon inflated at the tip, it “floats” forward and can wedge in a distal PA to estimate left-sided filling pressure.

Balloon includes transient inflation to obtain PAOP/PCWP (an LA pressure surrogate when conditions are met). Thermistor includes cardiac output by thermodilution; continuous CO/SvO₂ with specialized catheters. Refractory/complex shock (undifferentiated or mixed septic/cardiogenic/obstructive) where therapy escalations (pressors/inotropes/afterload/fluids) depend on filling pressures, CO/CI, SvO₂, SVR, PVR. Advanced heart failure includes decompensated HF with unclear volume vs afterload vs RV failure; evaluation for LVAD/heart transplant. Post-cardiac surgery or high-risk cardiac procedures with labile hemodynamics.

Hemodynamically stable patients; routine sepsis without right-heart complexity; when echo and arterial line already answer the question. Absolute includes no safe venous access; right-sided endocardial mass (e.g., thrombus/vegetation) in catheter path; mechanical tricuspid/pulmonic valve. Relative includes severe coagulopathy, endocarditis, LBBB (risk of complete heart block during RV passage), recent RV infarct/irritability. Flush all lumens; calibrate/zero transducer at phlebostatic axis (4th ICS mid-axillary). Advance leading to RV includes rise in systolic (15-30) with diastolic near 0; arrhythmias common here-advance promptly.

Pulse pressure offers insight into how much blood is being ejected with each cardiac cycle, filtered through the arterial system. These thresholds are context-dependent and should be interpreted alongside the clinical picture.

Pulse Pressure Variation is pPV is the respiratory cycle-induced variation in arterial pulse pressure (systolic - diastolic) in mechanically ventilated patients. Physiology includes positive-pressure inspiration decreased venous return leading to decreased RV filling leading to after a few beats decreased LV preload leading to decreased SV & PP. Expiration does the opposite. A key concept is that bigger swings in PP = ventricle operating on the steep part of the Frank-Starling curve leading to likely fluid responsive.

PPV ≥ 13% leading to fluid responsive likely. PPV ≤ 9% leading to fluid responsive unlikely. PPV 9-13% leading to gray zone leading to confirm with adjuncts. Low PPV leading to fluids unlikely to help; optimize pressors/inotropes/vent. Continuous & real-time when arterial line in place. Less Reliable When include Spontaneous breathing effort present, Arrhythmias (AF, frequent ectopy), Low Vt ventilation without challenge, Low driving pressure or poor compliance, and RV failure, pulmonary HTN, increased intra-abdominal pressure.