Question | Answer |
the apex of the heart is formed by the | tip of the left ventricle |
the base of the heart is found at approximately the level of | the second rib |
the anterior surface of the heart consists primarily of the | the right ventricle |
the inferior surface of the heart is formed by | the right and left ventricles |
blood pressure is determined by | cardiac output multiplied by peripheral vascular resistance |
the heart is divided into ____ chambers, but functions as a ___ sided pump | 4 chambers, 2 sided-pump |
which side of the heart is a low pressure system that pumps venous blood to the lungs? | the right side of the heart |
which side of the heart is a high-pressure system that pumps arterial blood to the systemic circuit | the left side of the heart |
the right atrium receives venous blood from the head, neck, and thorax via the | superior vena cava |
the right atrium receives blood via the lower body from the | inferior vena cava |
the right atrium receives venous blood from the heart muscle via the | coronary sinus |
the left atrium receives blood from the | pulmonary veins |
the _____ is the largest vein that drains the heart | the coronary sinus |
movement of blood from the left ventricle through the body is called | systemic circulation |
the thick, muscular middle layer of the heart wall that contains the atrial and ventricular muscle fibers necessary for contraction is | the myocardium |
which of the following are the semilunar valves | the aortic and pulmonic valves |
thin strands of thin connective tissue that extend from the AV valves to the papillary muscles and prevent the AV valves from bulging back into the atria during ventricular systole. these strands are called | the chordae tendineae |
blood leaves the left ventricle through which valve to the aorta? | the aortic valve |
blood flows from the right atrium through the ____ valve into the right ventricle | the tricuspid valve |
blood flows from the left atrium through the ____ valve into the left ventricle | the mitral valve |
the right ventricle expels blood through the _____ valve into the pulmonary trunk | the pulmonic valve |
the coronary arteries originate at the base of the | aorta, immediately above the leaflets of the aortic valve |
complete occlusion of the _______ coronary artery, also referred to as the "widow maker", usually results in sudden death | left main |
stimulation of alpha-adrenergic receptors results in | peripheral vasoconstriction |
stimulation of beta-2 receptors sites results in | relaxation of bronchial smooth muscle |
"Chronotropy" refers to an effect on | heart rate |
rapid ejection of blood from the ventricular chambers of the heart occurs because the ____ and _____ valves open | pulmonic and aortic valves |
when the left ventricle contracts, freshly oxygenated blood flows through the _____ valve into the ______ | aortic valve; aorta |
the left main coronary artery divides into the | anterior descending and circumflex branches |
the primary chemical mediator of the parasympathetic division of the autonomic nervous system is | acetylcholine (ACH) |
the right atrium receives deoxygenated blood from | the superior and inferior vena cava |
what do we call the period during which a heart chamber is contracting and blood is being ejected? | systole |
what do we call the period during which a heart chamber is relaxing and is filling with blood? | diastole (DIE-astole, DEAD, DOWN) |
which valve separates the right ventricle from the right atrium | the tricuspid valve |
define systole | contraction or ejection of blood from a chamber of the heart |
what is the term used to describe the percentage of blood pumped out of a heart chamber with each contraction | ejection fraction |
which law states, that to a point, the greater the volume of blood in the heart during diastole, the more forceful the cardiac contraction, and the more blood the ventricle will pump (stroke volume) | The Frank-Starling law |
what are the 4 electrolytes that influence cardiac function? | sodium (Na+), Potassium (K+), Calcium (Ca++), Chloride (Cl-) |
a conduction problem above the level of the bundle branches will largely affect | the P wave and the PR interval |
the period of time during the cardiac cycle when cells cannot respond to a stimulus, no matter how string it is, is called | the refractory period |
when referring to contraction and relaxation, depolarization is which? | contraction |
in most ECG leads, a normal Q wave is less than 0.04 s in duration and less than 1/3 the amplitude of the _____ waves in that lead | the R wave |
the point where the QRS complex and the ST segment meet is called | the junction or the j point |
when electrical activity is not detected on the ECG, a straight line is recorded. what is the term used to describe this straight line | the "baseline" or the "isoelectric line" |
in the limb leads, the ST segment is normally isoelectric, or less than _____ above or below the isoelectric line | 1 mm |
a unipolar lead consists of a positive electrode, a negative electrode, and a _____ ______ | reference point |
the cardiac action potential is a reflection of the difference in the concentration of what? | charged particles of a cell membrane at any given time |
in most patients, the SA and AV nodes are supplied by the ______ coronary artery | the right coronary artery |
the intrinsic rate of the AV junction is | 40-60 bpm |
how do you determine whether the atrial rhythm on an ECG tracing is regular or irregular? | compare P-P intervals |
______ is the ability of a cardiac pacemaker cells to spontaneously initiate an electrical impulse without being stimulated from another source (such as a nerve) | automaticity |
in the heart's conduction system the ____ receive(s) an electrical impulse from the bundle of His and relays it to the purkinje fibers in the ventricular myocardium | right and left bundle branches |
the ECG does not provide information about | the mechanical (contractile) function of the myocardium |
in the heart's conduction system the ____ receives an electrical impulse from the R and L bundle branches and relays it to the ventricular myocardium | purkinje fibers |
what does a QRS complex represent? | ventricular depolarization |
the normal pace maker of the heart is the | SA node |
the SA node is found in the | right atrium |
on an ECG what is the first negative deflection seen after the P wave | the Q wave |
where is the negative electrode placed in lead II? | right arm |
leads II, III, VF view the _____ surface of the left ventricle | inferior |
leads I, aVl, V5, and V6 view the _____ surface of the left ventricle | the lateral surface |
the absolute refractory period begins and ends where? | begins with the onset of the QRS comples and terminates at approximately the apex of the T wave |
QT interval is measured from | the beginning of the QRS complex to the end of the T wave |
in an adult, the normal duration of the QRS complex is | 0.10 s or less |
the intrinsic rate of the purkinje fibers is | 20-40 bpm |
the period during the cardiac cycle when cells cannot respond to a stimulus no matter how strong is called then | absolute refractory period |
the PR interval is considered prolonged if it is more than ____ in duration | 0.20 s |
the intrinsic rate of the SA node is | 60-100 bpm |
on the ECG the T wave represents | ventricular repolarization |
on the ECG the time necessary for the spread of an electrical impulse through the AV node, bundle of His, R & L bundle branches and the purkinje fibers is reflected by | the PR segment |
the PR interval usually lengthens or shortens as the heart rate increases? | shortens |
the portion of the ECG tracing between the QRS complex and the T wave is called | the ST segment |
where is the first positive deflection seen on the ECG after the P wave | the R wave |
where is the positive electrode placed in lead III | left leg or foot |
which leads are bi-polar leads? | I, II, III |
____ cells are working cells of the heart that contain contractile filaments and form the muscular layer of the atrial walls, and the thicker muscular layer of the ventricular walls | myocardial |
_____ cells are specialized cells of the electrical conduction system responsible for the spontaneous generation and conduction of electrical impulses | pacemaker |
when the cardiac muscle is stimulated, the cell is said to | depolarize |
the P wave represents | atrial depolarization |
QRS complex represents | ventricular depolarization |
what is the term used to describe the period of recovery that cells need after being discharged before they are able to respond to a stimulus | refractoriness |
what leads are on the chest | V1-V6 |
where is the ST segment measured? | from the end of the QRS complex to the beginning of the T wave |
U waves are thought to represent | repolarization of the purkinje fibers |
tall, peaked T waves observed on the ECG are most commonly seen in pts with | hyperkalemia |
the absolute refractory period is also known as | the effective refractory period |
the ability of cardiac muscles cells to respond to an external stimulus, such as that from a chemical, mechanic or electrical source is known as | excitability |
an ECG lead that has a positive and a negative electrode is called | bi-polar |
name the first positive wave deflection seen after the P wave | the R wave |
what is the inherent rate for the SA node | 60-100 bpm |
what is the inherent rate for the AV junction | 40-60 bpm |
what is the inherent rate for the ventricles | 20-40 bpm |
what are the 4 properties of cardiac cells? | automaticity, excitability, conductivity, contractility |
what is the normal duration of the QT interval | less than the RR interval |
which ECG leads view the heart in the horizontal plane, allowing a view of the front and left side of the heart | V1-V6 |
in sinus arrhythmia, a gradual increasing of the heart rate is usually associated with | inspiration |
in sinus arrhythmia a gradual decreasing of the heart rate is usually associated with | expiration |
the rate of sinus tachycardia is | greater than 100 bpm |
a strip shows a ventricular rate of 46, a regular rhythm, a PR interval of 0.14 s, a QRS duration of 0.06, and 1 upright P wave before each QRS. this rhythm is | sinus bradycardia |
a strip shows a ventricular rate of 128, a regular rhythm, a PR interval of 0.16 s, a QRS duration of 0.08, and 1 upright P wave before each QRS. this rhythm is | sinus tachycardia |
what are a few possible causes of sinus tachycardia | fever, pain, and anxiety |
what are a few possible causes of sinus bradycardia | increased intercranial pressure, beta blocker over dose |
The rate of a sinus rhythm is | 60 to 100 beats/min. |
The rate of a sinus bradycardia is: | less than 60 beats/min. |
What may cause a sinus bradycardia? | hypothermia |
Which of the following what ECG criteria for a sinus rhythm? | P waves that look alike, and upright in lead II, one before each QRS complex |
Management of a patient with a sinus tachycardia might include: | identification and treatment of the underlying cause |
what is meant by the term :controlled" atrial fibrilliation | when the overall ventricular rate is less than 100 bpm |
what is meant by the term "uncontrolled" atrial fibrillation | the overall ventricular rate is greater than 100 bpm |
how do we define multifocal atrial tachycardia | atrial and ventricular rhythms are irrgeular |
describe multifocal tachycardia | atrial and ventricular rhythms are irregular |
a delta wave is frequently seen with | wolff-parkinson-white syndrome |
what is the most common type of supraventricular tachycardia (SVT) | AV nodal reentrant tachycardial (AVNRT) |
atrial fibrillation is characterized by | an erratic, wavy baseline and irregular ventircular rhythm |
wolff-parkinson-white syndrome is associated with a | short PR interval, delta wave, and wide QRS |
sings and symptoms experienced during a tachydysrhythmia are usually primarily related to | decreased ventricular filling time and stroke volume |
how are frequent PAC's usually managed | correcting the underlying cause |
a wandering atrial pacemaker rhythm with a ventircular rate of 60-100/min may also be referred to as | mulitformed atrial rhythm |
to determine whether the ventricular rhythm is regular or irregular you should compare | R to R intervals |
what distinguishes atrial flutter from other atrial dynrhythmias | the "saw tooth" or picket-fence" appearance of wave forms before the QRS |
to determine whether the ventricular rhythm is regular or irregular compare: | R to R intervals |
where do all supraventricular dysrhymthias | above the bifurcation of the bundle of HIS |
which medication increases heart rate by accelerating the SA node discharge rate and blocking the vagus nerve? | atropine |
what is the primary waveform used to differentiate PJC's from PAC's is | the P wave |
common causes of junctional dysrhythmias may include acute coronary syndromes | digitalis toxicity |
in the cardiac cycle, a PJC occurs | early, before the next expected sinus beat |
an acceletrated juntional rhythm is identifies by a regular ventricular response | 61-100 |
a junctional escape rhythm occurs because of | the slowing of the rate of the heart's primary pacemaker |
the usual rate of nonparoxysmal junctional tachycardia is | 101-140 bpm |
the AV junction consists of the | AV node and nonbranching portion of the bundle of His |
depending on the severity of the pateint's signs and symptoms, management of slow rhythms originating from the AV junction may require intervention including: | atropine and/or transcutaneous spacing |
if the AV junction paces the heart, the electrical impulse must travel in which direction to activate the atria? | a backward direction or "retrograde" |
a noncompensatory pause often follows a PJC and represents the delay during which | the SA node resets it's rhythm for the next beat |
the term for 3 premature ventricular complexes (PVC's) occurring in a row at a rate of more than 100/min is | a run of ventricular tachycardia |
what does the QRS complex represent | ventricular depolarization |
what rhythm is described as an essentially regular rhythm with QRS complexes measuring .12 sec or greater; atrial rate not discernible, ventricular rate of 20-40 bpm | idioventricular rhythm |
a rapid, wide-QRS rhythm associated with pulselessness, shock or congestive heart failure should be presumed to be | ventricular tachycardia |
what is the rate of idioventricular rhythm | 20-40 bpm |
essentially regular ventricular rhythm with QRS complexes measuring .12 sec or greater, atrial rate not discernible, ventricular rate 41-100 bpm describes which rhythm? | AVIR: accelerated idioventricular rhythm |
what is initiated by a lower pacemaker site when the SA node slows or fails to initiate an impulse is called | an escape rhythm |
what consists of the AV node and non-branching portion of the bundle of His | the AV junction |
where are the pacemaker cells in the AV junction located? | near the non-branching portions of the bundle of His |
does the AV node contain pacemaker cells? | NO! |
what is the intrinsic rate of the AV junction? | 40-60 bpm |