Mixed Deck — All CCT Topics Flashcards

Which hand hygiene technique is required when caring for a patient with Clostridioides difficile (C. diff) infection?

Answer: Soap and water handwashing — alcohol-based hand sanitizers are NOT effective against C. diff spores

C. difficile produces hardy spores that are resistant to alcohol-based hand sanitizers. Soap and water mechanically removes spores from hands and is the only effective hand hygiene method for C. diff.

The formula to determine cardiac output, often known as CO, Q, or Qc, is as follows:

Answer: SV x HR = CO

Heart rate (HR) and stroke volume (SV), the amount of blood the heart expels with each beat, are combined to form carbon dioxide (CO).

When is it appropriate to activate the ECG machine's built-in artifact filters?

Answer: Only when proper technique cannot eliminate the artifact, and filter use must be documented

Filters should only be used as a last resort when technique cannot resolve artifact, and their use must be documented because filters can alter waveform morphology and potentially mask diagnostic findings.

What ECG characteristics are used to identify atrial flutter with 2:1 conduction?

Answer: Sawtooth flutter waves at approximately 300 bpm with a regular ventricular rate of approximately 150 bpm

Atrial flutter typically has an atrial rate of 250-350 bpm (classic: ~300 bpm) producing sawtooth flutter waves. With 2:1 conduction, every other flutter wave conducts to the ventricles, giving a ventricular rate of approximately 150 bpm.

What is the normal R-wave progression across the precordial leads (V1 through V6)?

Answer: R wave amplitude progressively increases from V1 to V5/V6, with transition (equal R and S) typically at V3 or V4

Normal R-wave progression shows a small r in V1 that gradually grows in amplitude through V2, V3, V4, and peaks at V5 or V6, with the R/S ratio transitioning from negative (S>R) to positive (R>S) typically at V3 or V4.

What are the ECG criteria for left bundle branch block (LBBB)?

Answer: QRS ≥ 0.12 seconds; broad monophasic R in lateral leads (I, aVL, V5-V6); rS or QS pattern in right precordial leads (V1-V2); absence of septal Q waves in lateral leads

LBBB criteria: QRS ≥ 0.12 seconds (complete LBBB), broad, notched or monophasic R in leads I, aVL, V5-V6, with no septal Q waves, and a deep rS or QS complex in V1-V2.

In a patient with pre-excited atrial fibrillation (AFib in WPW), what is the characteristic ECG appearance and why is this a medical emergency?

Answer: Very rapid (>200-300 bpm), irregularly irregular, wide and bizarre QRS complexes; dangerous because the accessory pathway can conduct extremely rapidly, potentially triggering VF

Pre-excited AFib produces a wide-complex, irregularly irregular tachycardia at extremely rapid rates (>200-300 bpm) because the accessory pathway, unlike the AV node, lacks rate-limiting properties and can conduct each AFib impulse to the ventricles, risking degeneration to VF.

A patient scheduled for a resting ECG reports having applied body lotion this morning. What is the best course of action for the CCT?

Answer: Clean the electrode sites with an alcohol wipe to remove the lotion.

Oils, lotions, and sweat on the skin can interfere with electrode adhesion and conductivity, leading to a poor-quality tracing. The proper procedure is to clean the skin at the electrode sites with an alcohol wipe and allow it to dry completely before applying the electrodes.

On an ECG, what is the characteristic appearance of a pacemaker spike followed by a wide QRS complex?

Answer: A thin vertical spike immediately followed by a broad, LBBB-morphology QRS greater than 0.12 seconds

Ventricular paced beats produce a sharp spike (the pacemaker stimulus artifact) immediately followed by a wide QRS complex resembling LBBB morphology, because ventricular activation spreads cell-to-cell rather than via the His-Purkinje system.

A patient's monitor displays a regular, wide-complex tachycardia at a rate of 180 bpm. Which of the following features, if present, would most definitively confirm the rhythm is Ventricular Tachycardia (VT) rather than Supraventricular Tachycardia (SVT) with aberrancy?

Answer: Presence of fusion and capture beats

While several criteria can suggest VT, the presence of AV dissociation, demonstrated by capture or fusion beats, is a pathognomonic sign of Ventricular Tachycardia. Capture beats are normal-looking QRS complexes that occur when a sinus beat is conducted to the ventricles during the tachycardia, and fusion beats are a hybrid of a sinus and ventricular beat.

What ECG characteristics define monomorphic ventricular tachycardia (VT)?

Answer: Three or more consecutive QRS complexes originating in the ventricles at a rate ≥ 100 bpm with identical QRS morphology from beat to beat

Monomorphic VT is defined as three or more consecutive ventricular beats at ≥100 bpm (typically 140-200 bpm) with uniform (identical) QRS morphology in each lead, indicating a single ventricular origin for each beat.

What is meant by 'poor R-wave progression' (PRWP) in the precordial leads?

Answer: The R wave fails to increase in amplitude across V1-V4, or the transition zone (R=S) occurs later than V4

Poor R-wave progression describes the ECG finding where R waves do not progressively increase in amplitude from V1 through V4 as expected, or where the transition from predominantly negative to predominantly positive QRS occurs later than normal (after V4).

What happens when Persantine (dipyridamole) is tested under Persantine-thallium stress?

Answer: It stimulates the heart to work harder, the way it would during exercise

Patients unable to exercise conventionally, as on a treadmill, can analyze blood flow to their hearts thanks to the use of persantine.

A patient experiences a vasovagal syncope episode during electrode placement for an ECG. What should the technician do first?

Answer: Ensure the patient's airway is maintained and lower their head (Trendelenburg or supine position), then call for help

In vasovagal syncope, the immediate priority is positioning the patient supine with legs elevated (Trendelenburg) to restore cerebral perfusion, secure the airway, and summon clinical help.

What advantages do thallium stress tests have over regular ECG stress tests?

Answer: More accurately identifies the specific areas of reduced blood flow in the heart

Nuclear stress tests, sometimes referred to as thallium stress tests, collect more detailed and precise data than straightforward ECG stress testing. When attempting to gauge the degree of coronary artery disease in a patient with a history of the condition, it is a useful test.

Which of the following heart conditions is brought on by the parasympathetic nervous system's actions?

Answer: Decreased rate of SA node pacing

The cardiac inhibitory effects of the parasympathetic nervous system include decreased SA node pacing, decreased conduction, and lower contraction force. The sympathetic nervous system generates an increase in contraction force and rate of conduction. By stimulating the sympathetic nervous system, the heart would contract more quickly, which would shorten the diastolic filling time.

On the ECG, a junctional escape rhythm typically presents with which rate and P wave pattern?

Answer: Rate 40-60 bpm; P waves absent, inverted (retrograde) before or after QRS, or hidden within the QRS, with narrow QRS morphology

The AV junction (His bundle area) has an intrinsic escape rate of 40-60 bpm. Junctional beats conduct to the ventricles normally via the His-Purkinje system (narrow QRS), but P waves are absent or retrograde (inverted in II, III, aVF).

A properly performed 12-lead ECG should be recorded at what standard paper speed?

Answer: 25 mm/second

The international standard paper speed for ECG recording is 25 mm/second, which makes each small square (1 mm) equal to 0.04 seconds and each large square (5 mm) equal to 0.20 seconds.

In a standard 12-lead ECG, lead aVR views the heart from which angle?

Answer: Right shoulder, looking toward the heart's base from above-right

Lead aVR is the augmented unipolar lead placed at the right arm, providing a view from the right shoulder looking down and toward the heart's base and right side. It is often inverted relative to other leads.

A 60-year-old male is scheduled for a maximal exercise stress test. Using the most common standard formula, what is his age-predicted maximum heart rate (MHR)?

Answer: 160 bpm

The most widely used and simplest formula to estimate maximum heart rate is 220 minus the patient's age. For a 60-year-old patient, the calculation is 220 - 60 = 160 bpm.