Alterations in Cardiovascular Function & Perfusion

Practice flashcards covering cardiovascular anatomy and physiology, hemodynamics, heart sounds, ECG analysis, and nursing management of common dysrhythmias.

Where is the point of maximal impulse (PMI) or apex of the heart located?

At the 5th intercostal space at the midclavicular line.

What are the three layers of the heart wall and their primary characteristics?

Endocardium (epithelial tissue lining the heart and valves), Myocardium (thickest muscular layer responsible for pumping), and Epicardium (serous layer that protects the heart).

What are the two layers of the pericardium?

The visceral layer (covers the heart surface) and the parietal layer (lines the sac and attaches to the great vessels, diaphragm, sternum, and vertebral column).

Which heart valves close during diastole and systole?

According to the transcript, the mitral valve closes during diastole, and the tricuspid valve closes during systole.

Which coronary artery branches supply the anterior left ventricle and the lateral left side?

The Left Anterior Descending (LAD) artery supplies blood to the anterior left ventricle, and the Circumflex artery supplies blood to the left lateral side (left atrium and posterior-lateral left ventricle).

What is the correct sequence of electrical impulse transmission through the cardiac conduction system?

SA node $\rightarrow$ AV node $\rightarrow$ Bundle of His $\rightarrow$ Right and Left bundle branches $\rightarrow$ Purkinje fibers.

How is Cardiac Output ($CO$) defined and calculated?

Cardiac Output is the total volume of blood ejected from a ventricle in liters per minute. It is calculated as $CO = SV \times HR$ (Stroke Volume $\times$ Heart Rate), with a typical normal value of $5\text{--}6\,\text{L/min}$.

What is the difference between preload and afterload?

Preload is the degree of ventricular stretching at the end of diastole (measured by pulmonary capillary wedge pressure, PCWP). Afterload is the resistance or pressure the ventricle must overcome to eject blood to the peripheral circulation.

What events generate the $S1$ and $S2$ heart sounds?

$S1$ ("Lub") signifies the closure of the mitral and tricuspid valves. $S2$ ("Dub") signifies the closure of the aortic and pulmonic valves.

What sound characterizes a pericardial friction rub and where is it best heard?

A grating sound typically heard over the left sternal border.

What are the normal duration ranges for the PR interval and QRS complex on an ECG analysis?

The PR interval is $0.12\text{ to }0.20\,\text{seconds}$, and the QRS complex duration is $0.06\text{ to }0.10\,\text{seconds}$ (or $< 0.12\,\text{seconds}$).

What are the age- and sex-based upper limits for a normal QT interval on an ECG?

Prepuberty: less than $0.45\,\text{seconds}$; Postpubertal males: less than $0.46\,\text{seconds}$; Postpubertal females: less than $0.47\,\text{seconds}$.

How is heart rate calculated using a 6-second ECG strip?

Count the number of QRS complexes in the 6-second strip and multiply that number by 10.

Which drug classes and medications can cause sinus bradycardia according to the lecture?

Parasympathomimetics (acetylcholine), beta blockers (metoprolol), digitalis glycosides (digoxin), calcium channel blockers (diltiazem), antiarrhythmics (amiodarone), chemotherapy agents (thalidomide), and lithium.

What is the IV atropine dosing protocol for an unstable client experiencing sinus bradycardia?

Administer IV atropine $1\,\text{mg}$ every $3\text{--}5\,\text{minutes}$, not to exceed a total dose of $3\,\text{mg}$.

What expected criteria define Sinus Tachycardia on an ECG?

Heart rate greater than $100\,\text{bpm}$ (range of $>100\text{ to }<150\,\text{bpm}$), regular rhythm, one consistently shaped P wave before each QRS complex, PR interval $0.12\text{ to }0.20\,\text{seconds}$, and QRS complex duration $0.06\text{ to }0.10\,\text{seconds}$.

What is the difference between bigeminy and trigeminy in premature ventricular contractions (PVCs)?

In bigeminy, every other complex is a PVC. In trigeminy, every third complex is a PVC.

When is catheter ablation indicated for a client experiencing PVCs?

If antiarrhythmic medications or beta blockers are not effective after 30 days.

What ECG feature defines a First-Degree Heart Block?

A prolonged PR interval greater than $0.20\,\text{seconds}$, resulting from abnormally slow or prolonged conduction through the AV node.

Which diagnostic test is used in Atrial Fibrillation to detect blood clots in the left atrium?

Transesophageal echocardiogram (TEE).

What are the characteristic ECG features of Atrial Flutter?

An overall regular rhythm with P waves replaced by multiple sawtooth or flutter waves, an atrial rate of $240\text{--}400\,\text{bpm}$, and a typically normal ventricular rate of $60\text{--}100\,\text{bpm}$.

What are the ECG interpretation findings associated with Supraventricular Tachycardia (SVT)?

A regular rhythm, heart rate of $100\text{--}220\,\text{bpm}$, narrow QRS complex less than $0.12\,\text{seconds}$, and an undiscernible P wave.

What is the IV adenosine administration protocol for Supraventricular Tachycardia (SVT)?

Administer IV adenosine $6\,\text{mg}$ over $1\text{ to }3\,\text{seconds}$ followed by a $20\,\text{mL}$ NS flush. If there is no change, administer a repeat dose of $12\,\text{mg}$ followed by a $20\,\text{mL}$ NS flush.