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CCRN Exam Practice Questions Cardiovascular With Correctly Explained Answers 2024
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CCRN Exam Practice Questions Cardiovascular With Correctly Explained Answers 2024
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CCRN Exam Practice QuestionsCardiovascular With Correctly Explained
Answers 2024
A .patient .is .in .cardiac .and .respiratory .arrest. .The .selection .of .medications .to .reestablish
.cardiac .function .would .stimulate .the .sympathetic .nervous .system .beta1 .receptors. .This
.stimulation .would .result .in .increased .automaticity .and .which .of .the
following?
a. .Increased .myocardial .contractility
b. .Decreased .left .ventricular .stroke .work
c. .Decreased .myocardial .oxygen .consumption
d. .Increased .left .ventricular .afterload .- .correct .answer.Correct .answer: .a
Rationale: .The .sympathetic .nervous .system .contains .alpha, .beta, .and .dopaminergic
.receptors .that .produce .various .responses .when .stimulated. .Stimulation .of .beta1
.receptors .increases .heart .rate, .conductivity, .and .myocardial .contractility. .Stimulation .of
.beta2 .receptors .produces .vasodilation .and .bronchodilation. .Alpha .receptors, .when
.stimulated,
produce .vasoconstriction. .Stimulation .of .dopaminergic .receptors .produces .a .vasodilating
effect .on .renal, .mesenteric, .coronary, .and .cerebral .vessels.
Test-Taking .Strategy: .Note .the .helpful .clue .in .the .stem: .stimulate .the .sympathetic .system
.and .recall .that .this .results .in .a .fight-or-flight .response—the .body .is .responding .to .survive.
.Stroke .volume .would .increase, .so .eliminate .option .b. .Afterload .would .increase, .but .this .is
.due .to .alpha .stimulation, .not .beta1 .stimulation, .so .eliminate .option .d. .Because .the .heart
.is .working .faster .and .harder, .the .myocardial .oxygen .consumption .does .increase, .so
.eliminate .option .c. .Remember .that .the .primary .effects .of .beta1 .receptors .are .to .increase
.heart .rate, .contractility, .and .rate .of .conduction. .Choose .option .a. .A .memory .aid .that .also
.may .help .is .this: .beta .1 .beta .2, .1 .heart .2 .lungs: .beta1 .affects .the .heart, .and .beta2 .affects
.the .lungs.
A .patient .arrived .in .the .emergency .department .with .complaints .of .chest .pain. .The .12-lead
.electrocardiogram .shows .ST .segment .elevation .in .leads .V3 .and .V4. .Occlusion .of .the
.affected .coronary .artery .most .likely .would .affect .perfusion .to .which .portion .of .the
conduction .system?
a. .Sinoatrial .(SA) .node
b. .Bachmann's .bundle
c. .Atrioventricular .(AV) .node
d. .Bundle .of .His .- .correct .answer.Correct .answer: .d
,Rationale: .ST .segment .elevation .in .leads .V3 .and .V4 .indicates .injury .to .the .anterior .wall,
.which .would .occur .with .occlusion .of .the .left .anterior .descending .(LAD) .artery. .In .most
.persons, .the .SA .node, .Bachmann's .bundle, .and .AV .node .are .supplied .by .the .right
.coronary .artery. .The .bundle .of .His .is .supplied .by .the .left .anterior .descending .artery. .This
.is .why .an
anterior .myocardial .infarction .may .cause .type .II .second-degree .AV .block .or .third-degree
.AV .heart .block .at .the .level .of .the .bundle .of .His.
Test-Taking .Strategy: .Note .that .options .a, .b, .and .c .are .part .of .the .supraventricular
.conduction .system. .They .usually .are .supplied .by .the .right .coronary .artery. .The .LAD
.artery .supplies .most .of .the .interventricular .conduction .system, .including .the .bundle .of .His
.and
the .bundle .branches.
Oxygen .delivery .(DO2) .is .the .product .of .which .of .the .following?
a. .PaO2, .hemoglobin, .mean .arterial .pressure
b. .SaO2, .hemoglobin, .cardiac .output
c. .SvO2, .cardiac .index, .SaO2
d. .PaO2, .mean .arterial .pressure, .SvO2 .- .correct .answer.Correct .answer: .b
Rationale: .Ninety-seven .percent .of .oxygen .is .attached .to .the .hemoglobin .molecule, .so
.the .SaO2 .(arterial .oxygen .saturation) .is .a .more .accurate .reflection .of .the .amount .of
.oxygen .in .blood. .The .PaO2 .represents .only .the .3% .that .is .dissolved .in .the .plasma. .The
.lungs .must .put .the .oxygen .in .the .blood, .the .hemoglobin .must .carry .the .oxygen, .and .the
.cardiac .output .is .a .reflection .of .how .well .the .heart .is .moving .the .blood .with .its .hemoglobin
.with .attached
oxygen. .SvO2 .(venous .oxygen .saturation) .is .a .reflection .of .the .oxygen .reserve. .SvO2 .is
.what .is .left .over .after .the .tissues .have .extracted .what .they .need. .The .mean .arterial
.pressure .is .a .reflection .of .organ .tissue .perfusion .pressure .but .does .not .indicate .anything
.about .the .amount .of .oxygen .in .that .blood.
Test-Taking .Strategy: .Oxygen .is .delivered .from .the .arterial .end, .so .choose .an .option .that
.has .SaO2 .instead .of .SvO2. .Also .remember .that .most .oxygen .is .carried .on .hemoglobin.
.Look .for .SaO2 .(not .PaO2) .and .hemoglobin. .The .only .option .with .both .of .these .is .option
.b.
Which .of .the .following .types .of .block .are .most .likely .after .an .anterior .wall .myocardial
.infarction .(MI)?
a. .Sinus .block
b. .Second-degree .atrioventricular .(AV) .block, .type .I
c. .Second-degree .AV .block, .type .II
d. .Third-degree .AV .block .with .junctional .escape .rhythm .- .correct .answer.Correct .answer:
.c
Rationale: .Anterior .MI .is .caused .by .a .left .anterior .descending .(LAD) .artery .lesion. .The
.LAD .artery .supplies .the .bundle .of .His .and .bundle .branches, .so .anterior .MIs .may .cause
.blocks .of .the .bundle .of .His .or .bundle .branches. .Second-degree .AV .block .type .II .is .a
.block .at .the .level .of .the .bundle .of .His. .If .this .patient .does .develop .a .third-degree .AV
.block, .it .would .be .at .the .level .of .the .bundle .of .His, .and .the .only .escape .rhythm .available
.below .the .bundle .of .His .is .a .ventricular .escape .rhythm.
, Test-Taking .Strategy: .The .sinus .node .is .supplied .by .right .coronary .artery .(in .55% .of
.people) .or .left .coronary .artery .(in .45% .of .people), .so .eliminate .option .a. .Type .I .AV .block,
.also .called .Wenckebach, .is .a .block .at .the .AV .node, .and .the .AV .node .is .supplied .by .right
.coronary .artery .(in .90% .of .people) .or .left .coronary .artery .(10%), .so .eliminate .option .b.
.The
LAD .artery .supplies .the .bundle .of .His, .and .blocks .in .this .area .would .eliminate .the
.possibility .of .junctional .escape .rhythms, .so .eliminate .option .d. .Choose .option .c.
A .patient .develops .atrial .fibrillation .after .abdominal .surgery. .Her .blood .pressure .falls .from
.110/70 .mm .Hg .to .92/68 .mm .Hg. .The .hypotension .is .related .to .which .of .the .following?
a. .Decrease .in .ventricular .contractility
b. .Hypovolemia
c. .Mural .thrombi
d. .Decrease .in .ventricular .filling .- .correct .answer.Correct .answer: .d
Rationale: .The .contribution .that .atrial .contraction .makes .to .ventricular .filling .volume .is
.approximately .15% .to .30%. .Atrial .fibrillation .results .in .quivering .but .not .contracting .atria.
.The .loss .of .15% .to .30% .of .diastolic .filling .volume .reduces .cardiac .output .and .can .have
.significant .hemodynamic .consequences. .Although .mural .thrombi .also .are .a .problem,
.they
result .in .an .embolic .phenomenon .rather .than .a .direct .decrease .in .cardiac .output. .The
.relationship .between .the .development .of .atrial .fibrillation .and .the .decrease .in .cardiac
.output .make .hypovolemia .and .decrease .in .contractility .less .likely.
Test-Taking .Strategy: .Relate .recent .changes .in .patient .status .to .recent .occurrences. .The
.patient .had .a .change .in .atrial .function, .so .select .an .option .that .results .in .loss .of .atrial
.contraction .or ."kick." .Choose .option .d.
A .shift .in .the .point .of .maximal .impulse .(PMI) .to .the .fifth .left .intercostal .space .at .the
.anterior .axillary .line .could .be .caused .by .any .of .these .conditions .except:
a. .left .ventricular .hypertrophy.
b. .right .tension .pneumothorax.
c. .pericardial .effusion.
d. .right .pleural .effusion. .- .correct .answer.Correct .answer: .c
Rationale: .In .pericardial .effusion .or .tamponade, .there .is .frequently .loss .of .palpability .of
.the .apical .impulse .because .of .the .fluid .layer. .Left .ventricular .hypertrophy, .right .tension
.pneumothorax, .and .a .right .pleural .effusion .could .shift .the .PMI .left .of .normal. .Normally .the
.PMI .is .located .at .the .fifth .left .intercostal .space .at .the .midclavicular .line.
Test-Taking .Strategy: .Look .for .the .process .that .would .not .shift .the .PMI .to .the .left .of .the
.normal .position. .Picture .the .process. .If .the .left .ventricle .is .big, .it .will .extend .farther .to .the
.left. .If .there .is .excessive .pressure .or .volume .on .the .right .side, .it .will .push .the .heart .toward
.the .left. .Pericardial .effusion .will .decrease .the .intensity .of .the .PMI .but .it .won't .shift .it.
Choose .option .c.
An .S4 .is .an .expected .physical .finding .in .which .of .the .following?
a. .Acute .myocardial .infarction
b. .Left .ventricular .failure
c. .Pericarditis
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