Patho_ch_33
1. ECG monitoring has been found to be more sensitive than a patient's report of symptoms when identifying transient ongoing myocardial ischemia. Why is this? a. Most ECG-detected ischemic events are clinically silent. b. The ECG can look at ischemic events from different directions. c. ECG monitoring is reliable only when the patient remains still. d. Most ECG-detected ischemic events cause a great deal of pain.
1. Answer:a RATIONALE:Persons with acute coronary syndrome are at risk for developing extension of an infarcted area, ongoing myocardial ischemia, and life- threatening arrhythrmias. Research has revealed that 80% to 90% of ECG-detected ischemic events are clinically silent. Thus, ECG monitoring is more sensitive than a patient's report of symptoms for identifying transient ongoing myocardial ischemia. Other answers are incorrect.
10. Antiarrhythmic drugs are classified into four major groups. The drugs in one may act similarly on cardiac conduction their hemodynamic action may vary significantly. Match the name of the drug to its classification and use in the following chart: Uses: supraventricular arrhythmias and tachyarrhythmias; slowing the sinoatrial node pacemaker and inhibiting conduction in the atrioventricular node; supraventricular and ventricular arrhythmias; treating ventricularar rhythrniasonly; treatment of serious ventricular arrhythmia Classifications: Class 1A, Class 1B, Class II, Class III, Class I 1. Procainimide 2. Atenolol 3. Amiodarone 4. Diltiazem 5. Lidocaine
1. Procainamide - supraventricular and ventricular arrhythmias - Class IA 2. Antenolo - Supraventricular arrhythmias and tachyardia rhythmias - Class II 3. Amiodarone - Treatment of serious ventricular arrhythmias - Class III 4. Diltiazem - slowing the sinoatrial node pacemaker and inhibiting conduction in the atrioventricular node - Class IV 5. Lidocaine - Treating ventricular arrhythmias only - Class IB
11. When a patient recurrent, either threatening arrhythmia originating supraventricularly or ventricularly, ablation therapy is an option for treatment. What does ablation therapy do? a. Removes hyper excitable cardiac tissue through open heart surgery b. Isolates and destroys arrhythmogenic cardiac tissue c. Identifies and excises ischemic cardiac tissue d. Uses a catheter technique to reestablish conductivityto mild infarcts
11. Answer: b RATIONALE: Ablation therapy is used for treating recurrent, life-threatening supraventricular and ventricular tachyarrhythmias. Ablative therapy may be performed by catheteror surgical techniques. It involves localized destruction, isolation, or excision of cardiact issue that is considered to be arrhythmogenic. Ablation therapy does not involve open heart surgery. It neither excises ischemic cardiac tissue nor reestablishes conductivity
the heart to respond to the increased demands of exercise in a controlled and monitored environment. Not only do exercise stress tests show changes in heart rate, blood pressure, and perceived level of exercise, but they have also been found useful in determining what? a. ECG ischemic-type ST-segment changes b. ECG ischemic-type QRS changes c. ECG documented conduction abnormalities d. ECG documented hemodynamic hyper reactions
9. Answer:a RATIONALE: This technique provides information about changes in heart rate, blood pressure, respiration, and perceived level of exercise. It is useful in determining exercise-induced alterations in hemodynamic response and ECG ischemic-type ST-segment changes and can detect and classify disturbances in cardiac rhythm and conduction associated with exercise. exercise stress test do not determine any of the other answers.
4. Atrial fibrillation is the most common chronic arrhythmia whose incidence increases with age. Atrial fibrillation may present as asymptomatic to severe symptomatology. What is the treatment of atrial fibrillation dependent on? Mark all that apply. a. Recency of onset b. Etiology c. Persistence of arrhythmia d. Size of pulse deficit e. Atrial rate
Answer: a, b, c RATIONALE: The treatment of atrial fibrillation depends on its cause, recency of onset, and persistence of the arrhythmia.The size of the pulse deficit and the atrial rate are not variables in treatment of atrial fibrillation.
A Holter monitor is a small ECG recording device used for long-term monitoring of cardiac activity, usually for up to 48 hours. These devices are used in correlation with event markers (on the device itself) and activity logs,or diaries of the person's activities. What cardiac problems is a Holter monitor useful in documenting? Mark all that apply. a. Conduction abnormalities b. Acquired cardiac deficiencies c. Congenital cardiac problems d. ST-segment changes e. PR interval changes
Answer: a, d RATIONALE: Holter monitoring is useful for documenting arrhythmias, conduction abnormalities, and ST-segment changes.
2. Respiratory sinus arrhythmiais considered a more optimal rhythm than a rhythm where all RR intervals are equal. In respiratory sinus arrhythmia,what is the variation in cardiac cycles related to? a. Intraabdominal pressure changes that occur with respiration b. Intrathoracic pressure changes that occur with respiration c. Intraabdominal pressure changes due to vagalnerve stimulus d. Intrathoracic pressure changes due to inadequate oxygenation
Answer: b RATIONALE: Today, it is accepted that a more optimal rhyttunis respiratory sinus arrhythmia. Respiratory sinus arrhythmia is a cardiac rhythm characterized by gradual lengthening and shortening of RR intervals. This variation in cardiac cycles is related to intrathoracic pressure changes that occur with respiration and resultant alterations in autonomic control of the sinoatrial node. The other answers do not cause the variafion in cardiac related to sinus cycles respiratory arrhythmia.
3. In children,what is sick sinus syndrome most commonly associated with? a. Congenital heart defects prior to corrective cardiac surgery b. Destruction of the sino atrial node c. Congenital heart defects following corrective cardiac surgery d. Destruction of the atrioventricular node
Answer: c RATIONALE: Sick sinus syndrome is a term that describes a number of forms of cardiac impulse formation and intraatrial and atrioventricular conduction abnormalities. In children, the syndrome is most commonly associated with congenital heart defects, particularly following corrective cardiac surgery.
7. Brugada syndrome,an autosomal dominant disorder, manifests in adulthood as ST-segment elevation, right bundle branch block, and susceptibility to ventricular tachycardia. In Brugada syndrome, the timing of cardiac events is significant. When do these cardiac events typically occur? a. During exercise b. When first arising in the morning c. Just before bed time at night d. During sleep or rest
Answer: d RATIONALE: The disorder typically manifests in adulthood with very incomplete penetrance, and a high percentage of mutation carriers are asymptomatic. Cardiac events typically occur during sleep or rest. Cardiac events during exercise, on arising in the morning, and iust before bed time at night are not indicative of Brugada syndrome.
5. Torsade de pointes is a specific type of polymorphic ventricular tachycardiain which the polarity of the QRS complex swings between positive and negative, often on a beat-to beat basis. It is the result of the long QT syndrome and can cause sudden cardiac death. Which medication is not linked to torsade de pointes as a causative agent? a. Verapamil b. Procainamide c. Digitalis d. Tetracycline
Answer: d RATIONALE: The long QT syndrome(LQTS)is characterized by prolongation of the QT interval that may result in a characteristic type of polymorphic ventricular tachycardia called torsade de pointes and sudden cardiac death. Torsade de pointes (twisting or rotating around a point) is a specific type of ventricular tachycardia.The term refers to the polarity of the QRS complex, which swings from positive to negative and vice versa. The QRS abnormality is characterized by large bizarre polymorphic multiformed QRS complexes that vary, often from beat to beat,in amplitude and direction, as well as in rotation of the complexes around the isoelectric line. Medications linked to LQTS include digitalis, antiarrhythmic agents (e.g., arniodarone, procainarnide, quinidine), rhythm associated with exercise. Exercise stress tests do a, b, c not determine any of the other answers. Procainamide Supraventricular and ventricular arrhythmias Supraventricularar- Class IA Class III Class IB depends on its cause, recency of onset, and perrhythmias and tachyarsistence of the arrhythmia.The size of the pulse deficit and the atrial rate are not variables in treatment of atrial fibrillation. Amiodarone Lidocaine rhythmias Treatment of serious ventricular arrhythmias Slowing the sinoatrial node pacemaker and inhibiting conduction in the atrioventricular node verapamil (calcium channel blocker), haloperidol (antipsychotic agent), and erythromycin (antibiotic).
6. In second-degree atrioventricular block, there is a relationship between the P waves and the QRS complex resulting in recurring PR intervals. What does this mean? a. The association of P waves and QRS complexes is not random. b. The relationship between the P waves and the QRS complexes is a wideningPR interval. c. The association of P waves and QRS complexes is random. d. The relationship between the P waves and the QRS complexes is a narrowing PR interval.
answer: a RATIONALE: A distinguishing feature of second- degree atriovenlricular block is that conducted P waves relate to QRS complexes with recurring PR intervals; that is, the association of P waves with QRS complexes is not random. The other answers are not correct.
