Cardiovascular Pathophysiology, ECG Interpretation, and Cardiac Revascularization

Comprehensive practice flashcards defining key vocabulary, diagnostic criteria, clinical cutoffs, and pathophysiological mechanisms for hypertension, dyslipidemia, metabolic syndrome, ECG interpretation, and myocardial revascularization.

Hypertension

A chronic medical condition characterized by a resting systolic blood pressure of $130\,\text{mmHg}$ or greater, or a resting diastolic blood pressure of $90\,\text{mmHg}$ or greater.

Mean Arterial Pressure (MAP) Formula

The physiological relationship represented by the equation $\text{MAP} = \text{CO} \times \text{TPR}$, where CO is cardiac output and TPR is total peripheral resistance.

Essential Hypertension

A primary form of hypertension that develops gradually and is characteristically associated with a normal cardiac output and an elevated total peripheral resistance.

SPRINT Trial

A major clinical study providing evidence for establishing a target systolic blood pressure that is $15\%$ lower than previous clinical recommendations.

Hypercholesterolemia

An unhealthy, pathologically elevated plasma concentration of cholesterol.

Hypertriglyceridemia

An unhealthy, pathologically elevated plasma concentration of triglycerides.

Dyslipidemia

A state of abnormal plasma lipid concentrations, which may encompass either pathologically high or low lipid levels.

Apolipoproteins

Protein components that provide structural integrity to lipoproteins, facilitate functional roles, and activate or inhibit key enzymes in lipid metabolism.

Metabolic Dyslipidemia Endothelial Effects

Vascular endothelium alterations triggered by sustained elevated bloodborne fatty acids, producing reduced nitric oxide production, induced adhesion characteristics, facilitated oxidative damage, inflammation, and diminished vascular compliance.

Familial Lipoprotein Lipase Deficiency

A familial hypertriglyceridemic disorder characterized clinically by abdominal pain, acute pancreatitis, and milky-appearing plasma.

Xanthomas

Cutaneous lipid deposits presenting as physical manifestations of familial hypercholesterolemia.

Metabolic Syndrome

A cluster of interrelated cardiometabolic risk factors occurring together more frequently than expected by chance, primarily stemming from obesity and insulin resistance.

Normal-Weight Obesity

The presence of abdominal obesity in an individual with normal body weight, which carries a strong association with elevated cardiovascular risk.

Mitochondrial Dysfunction in Metabolic Syndrome

A structural and metabolic state where obese, sedentary, and insulin-resistant individuals possess smaller, fewer mitochondria with impaired function, resulting in energy deficit and decreased ATP production.

QRS Complex

The electrocardiographic waveform denoting ventricular depolarization, during which atrial repolarization also takes place but remains obscured.

T-Wave

The electrocardiographic deflection that represents the repolarization of the ventricles.

ECG Paper Time Calibration

Horizontal time intervals measured at a standard paper speed of $25\,\text{mm/s}$, where one small block equals $0.04\,\text{seconds}$ and one large block equals $0.2\,\text{seconds}$.

Corrected QT (QTc) Formula

The formula used to assess ventricular repolarization corrected for heart rate: $\text{QTc} = \frac{\text{QT}}{\sqrt{\text{R-R}}}$.

Mason-Likar 12-Lead System

A modified electrode placement system specifically utilized for monitoring 12-lead electrocardiography during exercise stress testing.

Dubin's Triplicates

A rapid method for estimating heart rate on an ECG strip based on consecutive large block demarcations: $300, 150, 100, 75, 60, 50\,\text{bpm}$.

Sinus Arrhythmia

A cardiac rhythm wherein each QRS complex is preceded by a normal P wave, but R-R intervals vary in length across the tracing.

Wandering Pacemaker

An atrial rhythm disorder identifiable on an ECG by varying P wave morphology from beat to beat.

Premature Ventricular Contraction (PVC)

An ectopic ventricular impulse identifiable on an ECG by a wide, abnormally configured QRS complex without a preceding P wave.

Bigeminy

An arrhythmia pattern characterized by every alternating beat being a premature ventricular contraction (PVC).

Trigeminy

An arrhythmia pattern characterized by every third beat being a premature ventricular contraction (PVC).

First-Degree AV Block

An atrioventricular conduction abnormality defined by a constant, prolonged PR interval exceeding $0.2\,\text{seconds}$.

Mobitz I (Second-Degree AV Block)

A form of second-degree heart block marked by progressive lengthening of the PR interval until a QRS complex is completely dropped.

Mobitz II (Second-Degree AV Block)

A conduction failure marked by the sudden intermittent drop of a QRS complex without prior progressive lengthening of the PR interval.

Third-Degree AV Block

Complete heart block characterized by total dissociation between atrial activity (P waves) and ventricular activity (QRS complexes).

Wolff-Parkinson-White (WPW) Syndrome

A congenital preexcitation syndrome characterized by an accessory pathway that produces a shortened PR interval and a classic delta wave.

Hyperkalemia ECG Manifestation

An electrolyte disturbance visible on an electrocardiogram as tall, peaked, narrow T waves.

Hypokalemia ECG Manifestation

An electrolyte disturbance characterized on an ECG tracing by the appearance of a prominent U wave.

Right Bundle Branch Block (RBBB)

An intraventricular conduction defect identified by a widened QRS complex presenting with an $R\text{-}R'$ ('R-R prime') pattern in leads $V_1$ and $V_2$.

Left Bundle Branch Block (LBBB)

An intraventricular conduction defect identified by a widened QRS complex exhibiting notching of the R wave in leads $V_5$ and $V_6$.

Left Ventricular Hypertrophy (Voltage Criterion)

An ECG diagnostic marker defined by the depth of the S wave in lead $V_1$ or $V_2$ plus the height of the R wave in lead $V_5$ or $V_6$ summing to $35\,\text{mm}$ or greater.

Myocardial Ischemia (ECG)

A condition of myocardial oxygen deficiency due to inadequate blood flow, typically manifested on an ECG as symmetrical T wave inversion.

Myocardial Injury (ECG)

Acute myocardial infarction tissue injury identifiable on an ECG tracing by significant ST segment elevation.

Pathological Q Wave

An ECG sign of necrotic or scarred myocardial tissue from a past infarction, characterized by a Q wave exceeding $1\,\text{little block}$ ($0.04\,\text{seconds}$) in width or occupying greater than $\frac{1}{3}$ the height of the entire QRS complex.

Coronary Artery Bypass Surgery (CABS)

A surgical revascularization procedure using a venous graft from the arm or leg, or an arterial graft, to re-establish blood flow past an occluded coronary artery segment.

Percutaneous Coronary Intervention (PCI)

A catheter-based revascularization approach involving balloon dilation, rotational or directional atherectomy, or laser interventions, commonly paired with stent delivery.

Ischemic Preconditioning

A cardioprotective strategy consisting of $5\,\text{minutes}$ of cuff occlusion at suprasystolic pressure ($200\,\text{mmHg}$) with $3\text{--}5\,\text{minutes}$ reperfusion intervals before cardiac surgery to diminish peri- and post-operative infarct size.