ABCM CVRN-BC · Levels I and II
You choose the destination.
The system chooses the route.
Set the exam date, find the holes, then work the queue in the order the blueprint says matters.
Tell it when your exam is and how much time you actually have. It works out the pace, finds what you do not know, then routes your study toward what is weakest and most heavily weighted. Everything below shares one set of progress.
Weakness Dashboard
Readiness by blueprint weight, the mastery mix, and the queue.
Where you standMastery OS
Set your exam date. Get a pace, a plan, and today’s work.
Plan · DashboardECG Lab
Live monitor with freeze and calipers, plus twelve 12-lead patterns.
Practice · DOK 1 to 4Study Notes
Physiology through bedside management, referenced and printable.
Read · 50 minWritten Gap Finder
Multiple choice across all fourteen domains, weighted the way the exam is.
Start herePractical Gap Finder
Worked off live tracings. Name it, measure it, localize it, decide.
Start herePractice Exams
Ten scored forms drawn from a reserved item pool.
Score estimateFirst time here
Four steps, in this order.
- Open Mastery OS and set your exam date, days per week, and minutes per day. You get a pace and an honest verdict on whether it fits.
- Run the Gap Finder. Rate yourself by domain, then answer the diagnostic. It does not take your self-rating at face value.
- Work the Right now queue. It is ranked by blueprint weight, how badly a thing is missed, and how long since you touched it.
- Sit a Practice Exam every second week. Read the domain breakdown, not just the score.
ECG & CVRN Review Course · MedMasters Collaborative
CVRN Mastery OS
ABCM CVRN-BC. You choose the destination, the system chooses the route.
Tell it when your exam is and how much time you actually have. It works out the pace, runs a gap finder across every competency on the blueprint, then routes your study toward what is weakest and most heavily weighted first. Ten scored practice exams sit in a separate item pool so a score is an estimate, not a memory test.
Set the target
Everything downstream is computed from these five answers. Change them any time and the plan recalculates.
Your plan
Week by week
| Week | Focus | Competencies | Recall | Milestone |
|---|
The pace assumes first-pass learning plus spaced review. Roughly 65 percent of your minutes go to new competencies and 35 percent to review, because content you learned in week one is worth nothing on exam day if it is not retrieved again before then.
Two gap finders, because two things fail independently
Knowing the content and reading a tracing are separate skills. Candidates fail on either one, and a single blended number hides which. So they are run separately, scored separately, and never averaged together. Both draw from their own item pool, and neither touches the reserved practice exam pool, so nothing you see here inflates a later score estimate.
Written gap finder
Multiple choice across all fourteen blueprint domains, weighted the way the exam is weighted. Each run draws a different form.
Practical gap finder
Worked off live tracings in the ECG lab. Name the rhythm, measure with calipers, localize on the 12-lead, then decide and act.
Right now
Finish setup and run the gap finder, then this becomes the only screen you need.
Readiness
Weakness queue
Ranked by blueprint weight, how badly it is missed, how long since you touched it, and whether other competencies depend on it. The top row is what to do next.
| Priority | Competency | Domain | State | Weight |
|---|
Domains
Practice exams
Ten forms, each assembled proportional to the ABCM CVRN-BC blueprint from a pool reserved for exams only. No item appears in the practice or recall decks, and no item repeats across forms, so each score is an independent estimate. A full-length form is the honest estimate; the 30-item quick check is for a mid-week read.
Form
ECG & CVRN Review Course · MedMasters Collaborative
ECG Learning Lab
Live monitor, freeze and measure, 12-lead patterns
Run a rhythm on the monitor, freeze the sweep when you see something, then drop calipers on the strip and measure it. The 12-lead viewer renders the same generated beat across all twelve leads so you can see how one event looks from twelve angles. Practice runs in four depth levels, from naming a rhythm to managing a patient whose rhythm is changing.
Caliper measurement
- Interval
- not set
- Small boxes
- not set
- Rate if R to R
- not set
- Amplitude
- not set
Freeze the sweep, turn calipers on, then drag either marker across the ECG channel. Keyboard: tab to a marker, arrow keys move it, hold shift for fine steps.
The ECG channel runs at 25 mm per second: one small box is 40 ms, one large box 200 ms, and 10 mm of height is 1 mV at standard gain. The pleth and arterial channels are generated from the same beats, so a beat that fills poorly produces a weak pulse. When the pulse rate falls below the heart rate, that is a real pulse deficit, not a display error.
Findings
Tracings here are synthesized from a vector model so the teaching pattern is clean and repeatable. They show what a pattern looks like, not what a specific patient looked like. Before any high-stakes item goes live, swap in a real de-identified tracing.
Press New question to begin.
Practical gap finder
Reading a tracing is a separate skill from knowing the content, and the two fail independently. This run is twenty items worked directly off a strip or a 12-lead: name it, measure it, localize it, decide what to do. None of it is multiple choice about a written description of a tracing.
Run it more than once. Each run pulls a different form, and the report compares this run against every earlier one, so you can tell a real weak spot from a small sample that happened to land badly.
ECG spine mastery
These five strands are the ECG spine from the competency framework. They write to the same browser store Mastery OS reads, so progress here shows up on the main dashboard.
Progress is stored in this browser only. Nothing is sent anywhere and no identifying information is recorded.
ECG & CVRN Review Course · MedMasters Collaborative
CVRN Study Notes
Basic science through advanced clinical practice. Every chapter runs the same route: the physiology first, then what changes in disease, then what it looks like at the bedside, then the guideline pathway stated explicitly, then questions where every option is explained, the wrong ones included.
The page opens as an outline. Nothing is hidden or locked, every section is one click away and Open everything is always available. Sections carry a time estimate so you can pick what fits the time you actually have.
Search filters sections by their text. Printing gives the complete document with every section open and every rationale shown.
Chapter 1 · L1 14% · L2 8% of the exam
Conduction and the Basic ECG
From pacemaker cell to rhythm strip
Conduction and the Basic ECG
question bank
Rhythm interpretation answers three questions, in this order:
- Origin. Where did the impulse begin?
- Conduction. What path did it take to the ventricles?
- Timing. How long did each step take?
These three answers determine the rhythm. Naming it is the last step, not the first.
Key points
- Pacemaker cells have no stable resting potential. They drift toward threshold on their own.
- Phase 4 drift. Inward sodium and calcium exceed outward potassium. This is the funny current.
- Fastest drift wins. The steepest phase 4 slope reaches threshold first and sets the rate, normally the sinoatrial node.
- Everything else is a backup. Lower sites only surface when the site above them fails.1,2
| Site | Intrinsic rate (per minute) | ECG appearance if it takes over |
|---|---|---|
| Sinoatrial node | 60 to 100 | Upright P wave preceding every QRS in lead II |
| Atrial focus | 60 to 80 | Abnormally shaped or inverted P wave, narrow QRS |
| Atrioventricular junction | 40 to 60 | Narrow QRS, P wave absent, inverted, or following the QRS |
| Purkinje system or ventricular myocardium | 20 to 40 | Wide QRS, no associated P wave |
The faster site suppresses the slower ones. A junctional or ventricular rhythm therefore means the sinoatrial node has failed, or conduction from it has been blocked.1,7
The conduction pathway, in sequence:
- The sinoatrial node depolarises.
- The impulse spreads across both atria, producing the P wave.
- The atrioventricular node delays conduction. This delay allows atrial emptying to complete before ventricular systole, and it accounts for most of the PR interval.
- The bundle of His, the right and left bundle branches, and the Purkinje fibres conduct rapidly through both ventricles, producing a narrow QRS complex.
Clinical consequence. An impulse that skips this rapid pathway travels myocyte to myocyte, which is slower. A QRS of 0.12 seconds or more means abnormal ventricular activation. Four causes:
- P wave. Atrial depolarisation. Upright in lead II indicates a sinus or high atrial origin conducting downward.
- PR interval. Onset of P to onset of QRS. Normal 0.12 to 0.20 seconds, which is three to five small boxes.
- QRS complex. Ventricular depolarisation. Normal under 0.12 seconds.
- ST segment. The plateau phase of the ventricular action potential. Normally isoelectric with the baseline.
- T wave. Ventricular repolarisation.
- QT interval. Total duration of ventricular depolarisation and repolarisation. Shortens as rate increases, which is why it is rate corrected.
Atrial repolarisation occurs during the QRS complex and is not normally visible.2,3
Memory tool
Five questions, same order, every strip:
- Rate
- Regularity
- P waves present and related to the QRS
- PR interval
- QRS width
Naming the rhythm before completing all five is the most common source of misinterpretation.
Standard recording is 25 mm per second at a calibration of 10 mm per millivolt. One small box is 0.04 seconds, one large box is 0.20 seconds.
- Regular rhythm. Rate equals 300 divided by the number of large boxes between two R waves, or 1500 divided by the number of small boxes.
- Irregular rhythm. Neither shortcut applies. Count QRS complexes in a six second strip and multiply by ten.
- QT correction. Bazett formula: QTc equals QT divided by the square root of the R to R interval in seconds. A QTc above approximately 500 ms is associated with markedly increased risk of torsades de pointes.
All three degrees answer two questions: does every atrial impulse reach the ventricles, and is the PR interval constant?
- First degree. PR interval greater than 0.20 seconds, constant, with every P wave conducted. A conduction delay rather than a true block.
- Second degree, Mobitz type I (Wenckebach). PR interval lengthens progressively until one P wave is not conducted, then the sequence resets. The lesion is usually within the atrioventricular node. Often responds to atropine.
- Second degree, Mobitz type II. PR interval constant, then a P wave fails to conduct without warning. The lesion is usually infranodal. Carries a risk of progression to complete block, and the escape rhythm below the lesion is slow and unreliable.
- Third degree (complete). No atrial impulses conduct. P waves and QRS complexes occur at independent rates with no fixed relationship. This atrioventricular dissociation is the diagnostic finding.
The distinction that changes management
- Nodal lesion (first degree, Mobitz I): atropine usually works. The escape below it is reliable.
- Infranodal lesion (Mobitz II, complete block): atropine frequently fails. The escape is slow and unreliable.
- Therefore: in Mobitz II and complete block, pacing capability is prepared at the same time atropine is given, not after it disappoints.8,5
Memory tool
Longer, longer, longer, drop, then you have a Wenckebach. Constant PR with a dropped beat is Mobitz II. P waves and QRS complexes marching independently is third degree. The distinguishing step in all three is measuring the PR interval across several consecutive beats rather than looking at one complex.
At the bedside
Treatment follows symptoms, not the number. A rate of 40 in a well perfused, asymptomatic patient is a finding. A rate of 52 with hypotension, altered mental status, ischaemic chest discomfort, or acute heart failure meets the definition of symptomatic bradycardia and is treated.
Sequence for symptomatic bradycardia: atropine 1 mg intravenous, repeated every three to five minutes to a maximum of 3 mg, while preparing transcutaneous pacing. If atropine is ineffective, proceed to transcutaneous pacing or a dopamine or epinephrine infusion.8
A monitored patient has a ventricular rate of 44. The PR interval measures 0.16 seconds and is identical on every conducted beat, and every third P wave is not followed by a QRS complex. The patient is diaphoretic with a blood pressure of 78 over 44. What is the priority action?
Observation is appropriate only when perfusion is adequate. Diaphoresis and a systolic pressure of 78 meet the criteria for symptomatic bradycardia, which requires treatment.
Correct. A constant PR interval with intermittently non-conducted P waves is Mobitz type II second degree block, which is usually infranodal. Atropine acts on the atrioventricular node and often fails when the lesion is below it, so pacing capability is prepared concurrently rather than after atropine fails.
Adenosine blocks conduction through the atrioventricular node. In a patient already failing to conduct through that node and who is hypotensive, this risks prolonged asystole. Adenosine is indicated for regular narrow complex tachycardia.
The hypotension here results from an inadequate ventricular rate rather than from hypovolaemia. Fluid will not raise a rate of 44, and giving it first delays the indicated treatment.
Why this matters
Two things are tested together: identifying Mobitz type II by a constant PR interval with dropped beats, and knowing that the anatomic level of the block determines whether atropine can be relied upon. Recognising the rhythm but managing it as Mobitz type I still produces the wrong action.
Memory tool
Constant PR with a dropped beat is Mobitz II, so Make ready to pace.
A rhythm strip shows a QRS duration of 0.16 seconds, no identifiable P waves, and a regular rate of 38. Which conclusion is best supported?
A sinus origin produces visible P waves. Their complete absence excludes it.
A junctional focus lies above the ventricles and conducts through the intact His-Purkinje system, producing a narrow QRS at 40 to 60 per minute. The QRS duration of 0.16 seconds excludes this.
Correct. A QRS of 0.16 seconds indicates activation outside the rapid conduction system, and a rate of 38 falls within the intrinsic ventricular escape range of 20 to 40. This is an escape rhythm maintaining cardiac output, so suppressing it with an antiarrhythmic would remove the only functioning pacemaker.
Atrial flutter produces organised atrial activity at approximately 250 to 350 per minute with a ventricular rate that is a fraction of it. Neither finding is present.
Why this matters
QRS width localises the origin and rate identifies which escape pacemaker is active. Reading them together locates the focus without memorising rhythm names, and it establishes the management principle: an escape rhythm is supported, never suppressed.
Memory tool
Wide means below. A narrow QRS used the conduction system, so the origin is at or above the junction. A wide QRS did not.
- 1. Hall JE, Hall ME. Guyton and Hall Textbook of Medical Physiology. 14th ed. Elsevier; 2021.
- 2. Tortora GJ, Derrickson B. Principles of Anatomy and Physiology. 16th ed. Wiley; 2020.
- 3. Marieb EN, Hoehn K. Human Anatomy & Physiology. 12th ed. Pearson; 2022.
- 5. Urden LD, Stacy KM, Lough ME. Critical Care Nursing: Diagnosis and Management. 9th ed. Elsevier; 2022.
- 7. Wagner GS, Strauss DG. Marriott’s Practical Electrocardiography. 13th ed. Wolters Kluwer; 2021.
- 8. Kusumoto FM, Schoenfeld MH, Barrett C, et al. 2018 ACC/AHA/HRS Guideline on the Evaluation and Management of Patients With Bradycardia and Cardiac Conduction Delay. Circulation. 2019.
- 9. Sandau KE, Funk M, Auerbach A, et al. Update to Practice Standards for Electrocardiographic Monitoring in Hospital Settings: A Scientific Statement From the American Heart Association. Circulation. 2017.
Chapter 2 · L1 22% · L2 14% of the exam
Coronary Artery Disease and Acute Coronary Syndrome
Oxygen supply, oxygen demand, and plaque rupture
Coronary Artery Disease and Acute Coronary Syndrome
question bank
Key points
- Extraction is already maximal. Myocardium takes 70 to 80 percent of delivered oxygen at rest, against about 25 percent elsewhere.
- No extraction reserve. The heart cannot meet extra demand by pulling more oxygen from the same blood.
- So flow is the only lever. Increased demand must be met by increased coronary blood flow.1,4
Coronary perfusion occurs during diastole. Systolic contraction compresses the intramyocardial vessels, particularly in the left ventricular subendocardium. Two clinical consequences follow directly:
- Tachycardia reduces perfusion. Increasing heart rate shortens diastole proportionally more than systole, so perfusion time falls at the moment demand is highest.
- The subendocardium is affected first. It is the last layer perfused and the most vulnerable to ischaemia, which is why subendocardial ischaemia produces ST depression rather than ST elevation.
Memory tool
Myocardial oxygen demand has three determinants: heart rate, contractility, and wall tension (preload and afterload). Every antianginal agent reduces at least one of them. Beta blockers reduce rate and contractility. Nitrates reduce preload. Afterload reducers reduce wall tension. Identifying which determinant a drug acts on gives you its indication without memorising a list.4
Stable angina. A fixed stenosis limits flow reserve. Perfusion is adequate at rest and inadequate on exertion, producing predictable, reproducible, exertional chest discomfort relieved by rest or nitroglycerin.12
Acute coronary syndrome. Plaque rupture or erosion exposes thrombogenic material to circulating blood. Platelets adhere and aggregate and a thrombus forms. What follows depends on whether the thrombus occludes the vessel completely.10,11
| Unstable angina | NSTEMI | STEMI | |
|---|---|---|---|
| Occlusion | Partial | Partial or transient | Complete |
| ECG | Normal, ST depression, or T wave inversion | Normal, ST depression, or T wave inversion | ST elevation, or new left bundle branch block |
| Troponin | Not elevated | Elevated | Elevated |
| Necrosis | None | Subendocardial | Transmural |
| Priority | Antithrombotic therapy, risk stratification | Antithrombotic therapy, early invasive strategy | Immediate reperfusion |
High sensitivity cardiac troponin detects very small quantities of myocardial injury. It has high sensitivity and lower specificity, so it excludes myocardial infarction well and confirms it less well. Troponin elevation occurs in sepsis, pulmonary embolism, myocarditis, renal impairment, tachyarrhythmia, and decompensated heart failure, none of which are coronary occlusion.11
- Myocardial injury is any troponin elevation above the 99th percentile upper reference limit.
- Acute injury requires a rise or fall across serial measurements, the delta.
- Myocardial infarction requires acute injury plus clinical evidence of ischaemia: symptoms, ECG changes, imaging evidence, or angiographic findings.
- Flat and high across serial draws, as in chronic kidney disease, is chronic myocardial injury.
- Rising over one to three hours is acute injury.
- The delta decides, not the single number.11
The guideline pathway
Reperfusion timing for STEMI, per the 2025 ACC/AHA acute coronary syndrome guideline:10
- At a PCI capable facility, target first medical contact to device within 90 minutes.
- Requiring transfer, target first medical contact to device within 120 minutes.
- If 120 minutes cannot be met, give fibrinolytic therapy within 30 minutes of arrival provided there is no contraindication, then transfer.
The decision rests on anticipated time to reperfusion, not on institutional preference.
Absolute contraindications to fibrinolysis: any prior intracranial haemorrhage, known structural cerebral vascular lesion or malignant intracranial neoplasm, ischaemic stroke within three months, suspected aortic dissection, active bleeding or bleeding diathesis, and significant closed head or facial trauma within three months.10
These typically occur between day two and day seven after a large infarct and present as abrupt decompensation in a previously stable patient.4,5
- Papillary muscle rupture. Acute severe mitral regurgitation. Sudden dyspnoea, new holosystolic murmur, pulmonary oedema, hypotension.
- Ventricular septal rupture. New harsh holosystolic murmur with a palpable thrill, biventricular failure, oxygen saturation step up between right atrium and right ventricle.
- Free wall rupture. Tamponade producing pulseless electrical activity.
- Cardiogenic shock. Most often after a large anterior infarct. Low cardiac output with elevated filling pressures.
Memory tool
A murmur that was not present the day before, in a patient who infarcted two to seven days ago, is a mechanical complication until proven otherwise.
A patient with a large anterior STEMI is on hospital day three. He develops sudden severe dyspnoea, a new loud holosystolic murmur at the apex, and a blood pressure of 82 over 50. Which explanation best fits?
Reinfarction presents with recurrent ischaemic chest discomfort and new ECG changes. It does not produce a new holosystolic murmur, which is the finding that directs the diagnosis elsewhere.
Correct. The timing, day two to seven after infarction, and the combination of a new holosystolic murmur with abrupt haemodynamic decompensation are characteristic. The left atrium has not dilated or become compliant, so the regurgitant volume transmits directly to the pulmonary circulation, producing pulmonary oedema and shock rather than gradual decline.
Post-infarction pericarditis occurs in this window but produces a pericardial friction rub and positional pleuritic chest pain, not a holosystolic murmur with hypotension and pulmonary oedema.
This attributes objective findings, a new murmur and a systolic pressure of 82, to a subjective cause. Hyperventilation produces neither.
Why this matters
Timing plus a new murmur plus haemodynamic collapse is the pattern. Acute and chronic mitral regurgitation behave differently because of atrial compliance: the chronically volume loaded atrium has remodelled and accommodates the regurgitant volume at lower pressure, while the acutely affected atrium has not.
Memory tool
Day two to seven, new murmur, sudden decompensation. Consider a mechanical complication before a medical one.
- 1. Hall JE, Hall ME. Guyton and Hall Textbook of Medical Physiology. 14th ed. Elsevier; 2021.
- 4. Libby P, Bonow RO, Mann DL, et al, eds. Braunwald’s Heart Disease: A Textbook of Cardiovascular Medicine. 12th ed. Elsevier; 2022.
- 5. Urden LD, Stacy KM, Lough ME. Critical Care Nursing: Diagnosis and Management. 9th ed. Elsevier; 2022.
- 10. Rao SV, O’Donoghue ML, Ruel M, et al. 2025 ACC/AHA/ACEP/NAEMSP/SCAI Guideline for the Management of Patients With Acute Coronary Syndromes. Circulation. 2025.
- 11. Thygesen K, Alpert JS, Jaffe AS, et al. Fourth Universal Definition of Myocardial Infarction (2018). Circulation. 2018.
- 12. Virani SS, Newby LK, Arnold SV, et al. 2023 AHA/ACC/ACCP/ASPC/NLA/PCNA Guideline for the Management of Patients With Chronic Coronary Disease. Circulation. 2023.
Chapter 3 · L1 20% · L2 13% of the exam
Heart Failure
Neurohormonal compensation and its consequences
Heart Failure
question bank
Cardiac output equals stroke volume multiplied by heart rate. Stroke volume is determined by three factors:
- Preload. Ventricular end-diastolic volume, the degree of myocardial fibre stretch before contraction.
- Afterload. The resistance the ventricle must overcome to eject.
- Contractility. The intrinsic force of contraction, independent of loading conditions.
Heart failure is the clinical syndrome in which cardiac structural or functional impairment prevents the ventricle from delivering an output adequate to metabolic demand, or does so only at elevated filling pressures.13 Both presentations follow from that definition: reduced forward output, and congestion from elevated filling pressures. Most patients have some of each.
The Frank-Starling relationship.
- Normal ventricle. More stretch improves actin and myosin overlap, so the next contraction is stronger, up to an optimum.
- Failing ventricle. The curve is flattened and shifted rightward.
- Result. The same added volume buys much less stroke volume and a much larger rise in filling pressure.
- Which is why volume loading a failing ventricle congests it instead of improving output.1,4
When cardiac output falls, the body activates the same reflexes it uses for hypovolaemia. Each is beneficial acutely and harmful when sustained.4,13
- Sympathetic activation. Increases heart rate and contractility and causes arteriolar vasoconstriction. Sustained, it increases myocardial oxygen demand, shortens diastolic filling and coronary perfusion time, raises afterload, and is directly cytotoxic to myocytes.
- Renin angiotensin aldosterone activation. Reduced renal perfusion triggers renin release. Angiotensin II causes vasoconstriction and aldosterone causes sodium and water retention. Sustained, it adds both preload and afterload and promotes myocardial fibrosis.
- Ventricular remodelling. Under sustained neurohormonal stimulation the ventricle dilates and hypertrophies into a geometry that is mechanically less efficient, converting an initial injury into a progressive disease.
Memory tool
Each of the four pillars of therapy opposes one of these compensations. That is why a beta blocker is given to a failing heart and an afterload reducer to a patient whose blood pressure is already low. The target is the neurohormonal cascade driving remodelling, not the pump itself.13
| Pillar | Mechanism opposed | Monitoring |
|---|---|---|
| ARNI, or ACE inhibitor or ARB | Renin angiotensin aldosterone system; ARNI additionally preserves natriuretic peptides | Potassium, creatinine, blood pressure, angioedema. A 36 hour washout is required when switching from an ACE inhibitor to an ARNI. |
| Beta blocker | Sympathetic activation and remodelling | Heart rate, blood pressure. Initiate at low dose and titrate slowly. Do not initiate during acute decompensation. |
| Mineralocorticoid receptor antagonist | Aldosterone mediated sodium retention and fibrosis | Potassium and renal function. The pillar most often responsible for hyperkalaemia. |
| SGLT2 inhibitor | Multiple, including natriuresis and altered myocardial substrate use | Volume status, genital mycotic infection, euglycaemic ketoacidosis. Benefit is independent of diabetes status. |
The rule that saves the regimen
- A modest creatinine rise after starting an ACE inhibitor, ARNI, or mineralocorticoid receptor antagonist is expected haemodynamics, not renal injury.
- It is not, by itself, a reason to stop the drug.
- The common harm is stopping everything when one number moves, which costs the patient the drugs that reduce mortality.13
Two independent questions determine management. The resulting four profiles were described by Stevenson and validated by Nohria and colleagues.14
- Is the patient congested? Wet or dry. Assessed by jugular venous pressure, orthopnoea, crackles, peripheral oedema, and hepatomegaly.
- Is the patient adequately perfused? Warm or cold. Assessed by pulse pressure, extremity temperature, mental status, and renal function.
| Dry (no congestion) | Wet (congested) | |
|---|---|---|
| Warm (perfused) | Profile A. Compensated. Continue therapy. | Profile B. Diuresis. |
| Cold (hypoperfused) | Profile L. Underfilled or over-diuresed. Cautious volume. | Profile C. Highest mortality. Decongestion with consideration of inotropic support. |
Profile C is the most frequently mismanaged. Four findings identify the cold patient:
- Narrow pulse pressure
- Cool extremities
- Altered mental status
- Rising creatinine
Crackles pull toward aggressive diuresis, but with low output that alone can further reduce perfusion.14,5
Readmission within 30 days is driven substantially by what occurs in the first two weeks after discharge. Effective teaching is specific and gives the patient an action threshold rather than general advice.13,6
- Daily weight. On waking, after voiding, in similar clothing, on the same scale. Consistency matters because the trend is the signal.
- Call threshold. A gain of two to three pounds in 24 hours, or five pounds in one week.
- Sodium. Guidance the patient can act on: read labels, avoid processed and restaurant foods, which contribute most dietary sodium.
- Symptom escalation. Distinguish what warrants a call today from what warrants emergency evaluation.
A patient admitted with decompensated heart failure has crackles to the mid lung fields, jugular venous distension, cool extremities, a narrow pulse pressure, and a creatinine that has risen from 1.1 to 1.7 mg/dL. Which management approach is most appropriate?
This addresses congestion and ignores perfusion. Cool extremities, narrow pulse pressure, and rising creatinine indicate hypoperfusion. Diuresis alone in profile C can further reduce cardiac output and worsen renal function.
Correct. Congestion with hypoperfusion is profile C, which carries the highest mortality of the four profiles. Congestion must be treated, but perfusion requires simultaneous support, which is why inotropic therapy is considered here and not in the warm and wet patient.
The rising creatinine suggests this, but crackles and jugular venous distension indicate volume overload. The renal impairment reflects low forward output and venous congestion, not hypovolaemia. Volume would worsen both.
Temporarily withholding beta blockade may be appropriate in low output states, but withholding all therapy while the patient is both congested and hypoperfused is not a management plan.
Why this matters
The profile framework exists to prevent the first option. Congestion and perfusion are assessed independently and both answers are required before a plan is made. Renal function that worsens during decongestion often reflects venous congestion rather than volume depletion, which is the opposite of what the creatinine alone suggests.
Memory tool
Wet means decongest. Cold means support forward flow. A cold and wet patient needs both, not one.
- 1. Hall JE, Hall ME. Guyton and Hall Textbook of Medical Physiology. 14th ed. Elsevier; 2021.
- 4. Libby P, Bonow RO, Mann DL, et al, eds. Braunwald’s Heart Disease: A Textbook of Cardiovascular Medicine. 12th ed. Elsevier; 2022.
- 5. Urden LD, Stacy KM, Lough ME. Critical Care Nursing: Diagnosis and Management. 9th ed. Elsevier; 2022.
- 6. Sole ML, Klein DG, Moseley MJ. Introduction to Critical Care Nursing. 8th ed. Elsevier; 2021.
- 13. Heidenreich PA, Bozkurt B, Aguilar D, et al. 2022 AHA/ACC/HFSA Guideline for the Management of Heart Failure. Circulation. 2022.
- 14. Nohria A, Tsang SW, Fang JC, et al. Clinical assessment identifies hemodynamic profiles that predict outcomes in patients admitted with heart failure. J Am Coll Cardiol. 2003.
References
Physiology and anatomy from current standard texts; clinical management from the most recent published guideline in each area. Guideline year is stated so a superseded version is obvious at a glance.
- Hall JE, Hall ME. Guyton and Hall Textbook of Medical Physiology. 14th ed. Elsevier; 2021.
- Tortora GJ, Derrickson B. Principles of Anatomy and Physiology. 16th ed. Wiley; 2020.
- Marieb EN, Hoehn K. Human Anatomy & Physiology. 12th ed. Pearson; 2022.
- Libby P, Bonow RO, Mann DL, et al, eds. Braunwald’s Heart Disease: A Textbook of Cardiovascular Medicine. 12th ed. Elsevier; 2022.
- Urden LD, Stacy KM, Lough ME. Critical Care Nursing: Diagnosis and Management. 9th ed. Elsevier; 2022.
- Sole ML, Klein DG, Moseley MJ. Introduction to Critical Care Nursing. 8th ed. Elsevier; 2021.
- Wagner GS, Strauss DG. Marriott’s Practical Electrocardiography. 13th ed. Wolters Kluwer; 2021.
- Kusumoto FM, Schoenfeld MH, Barrett C, et al. 2018 ACC/AHA/HRS Guideline on the Evaluation and Management of Patients With Bradycardia and Cardiac Conduction Delay. Circulation. 2019.
- Sandau KE, Funk M, Auerbach A, et al. Update to Practice Standards for Electrocardiographic Monitoring in Hospital Settings: A Scientific Statement From the American Heart Association. Circulation. 2017.
- Rao SV, O’Donoghue ML, Ruel M, et al. 2025 ACC/AHA/ACEP/NAEMSP/SCAI Guideline for the Management of Patients With Acute Coronary Syndromes. Circulation. 2025.https://www.ahajournals.org/doi/10.1161/CIR.0000000000001309
- Thygesen K, Alpert JS, Jaffe AS, et al. Fourth Universal Definition of Myocardial Infarction (2018). Circulation. 2018.
- Virani SS, Newby LK, Arnold SV, et al. 2023 AHA/ACC/ACCP/ASPC/NLA/PCNA Guideline for the Management of Patients With Chronic Coronary Disease. Circulation. 2023.
- Heidenreich PA, Bozkurt B, Aguilar D, et al. 2022 AHA/ACC/HFSA Guideline for the Management of Heart Failure. Circulation. 2022.https://www.ahajournals.org/doi/10.1161/CIR.0000000000001063
- Nohria A, Tsang SW, Fang JC, et al. Clinical assessment identifies hemodynamic profiles that predict outcomes in patients admitted with heart failure. J Am Coll Cardiol. 2003.
- Whelton PK, Carey RM, Aronow WS, et al. 2017 ACC/AHA/AAPA/ABC/ACPM/AGS/APhA/ASH/ASPC/NMA/PCNA Guideline for the Prevention, Detection, Evaluation, and Management of High Blood Pressure in Adults. Hypertension. 2018.
Weakness dashboard
Where the exam will cost you points
Every figure here is weighted by the CVRN-BC blueprint, so a weak domain worth 22 percent outranks a weak domain worth 4 percent. Nothing is scored until there is evidence for it.
Readiness by domain
Bar length is your mastery. Bar colour is depth of evidence, palest means barely tested. The number on the right is the domain's share of the exam.
Mastery mix
Every competency in scope, by state.
Readiness trend
One point per day you studied.
Coverage against the blueprint
Where your evidence is thin relative to what the exam weights. A short blue bar beside a tall orange one is a domain you have not tested enough.
Weakness queue
Ranked by blueprint weight, severity, time since you touched it, and whether other competencies depend on it.
ECG & CVRN Review Course. Prepared by Dr. Sharilyn Rennie for MedMasters Collaborative. Progress is stored in this browser only. No names, identifiers, or scores leave this device. Teaching material for certification preparation, not a clinical protocol.