Heart failure through pressure, perfusion and treatment
Connect filling pressure and perfusion to heart failure symptoms, distinguish EF phenotypes, and choose chronic and acute treatments through clinical cases.
Two patients can have the same breathlessness and pulmonary congestion while one has an EF of 25% and the other an EF of 60%. The first question is whether a cardiac abnormality explains the syndrome. The next questions are which pressure is high, whether organs are perfused, and which treatment changes the patient's course.
A preserved fraction does not guarantee an adequate stroke volume or a low filling pressure.
Separate the ejected fraction from filling pressure
Heart failure is a clinical syndrome caused by structural or functional cardiac disease, supported by evidence such as congestion, raised filling pressure or natriuretic peptides. EF is stroke volume divided by end-diastolic volume. It describes a proportion, not the absolute forward output, contractile health of every myocardial segment or pressure needed to fill the ventricle. Significant valve regurgitation further separates total ejected volume from effective forward flow. [1][4][26]
The denominator changes the meaning of the fraction
Dilated ventricle
End-diastolic volume 180 mL End-systolic volume 126 mL
Stroke volume 54 mL EF 54 ÷ 180 = 30%
Smaller filling volume
End-diastolic volume 90 mL End-systolic volume 36 mL
Stroke volume 54 mL EF 54 ÷ 90 = 60%
These ventricles eject the same volume. Neither calculation tells you filling pressure. A stiff chamber can require high pressure to accept even a modest volume. Values illustrate arithmetic, not diagnostic cutoffs for chamber size. [26]
Common guideline and trial categories are HFrEF at EF ≤40%, HFmrEF at 41% to 49%, and HFpEF at ≥50%. With EF above 40%, seek objective evidence of increased filling pressure at rest or with exertion. The June 2026 second universal definition emphasizes clinical context and EF trajectory rather than rigid boundaries. Keep the conventional ranges to interpret existing evidence, while recognizing measurement variation and treatment benefit across adjacent ranges. [1][4]
HFrEF often combines impaired contraction and ventricular dilation. HFpEF is heterogeneous: delayed relaxation, increased stiffness, vascular dysfunction, obesity, chronotropic limitation and atrial or right heart abnormalities can contribute. Concentric hypertrophy is common with longstanding hypertension but is not required. An S3 can accompany rapid filling into a volume-loaded chamber; an S4 reflects atrial contraction against a resistant ventricle and is absent in atrial fibrillation. Neither sound alone identifies an EF category. [33][1][3]
Why compensation becomes harmful
Reduced effective arterial perfusion activates sympathetic signaling and the renin-angiotensin-aldosterone system. Vasoconstriction supports pressure while increasing afterload; salt and water retention support filling while aggravating congestion. Sustained signaling promotes remodeling. Natriuretic peptides oppose these effects through natriuresis and vasodilation, but the response does not reliably restore normal circulation. A patient with low-output congestive LV failure may have a low cardiac index, high pulmonary capillary wedge pressure and high systemic vascular resistance. Stable HFrEF need not have that entire profile. [1][10]
Try it here · Checkpoint 1 of 3
Make your prediction before reading the choices. A first attempt is just a starting point.
Case 1
Show answer and explanations for case 1
A. Stroke volume is 100 mL because end-diastolic volume is the amount present before systole and therefore all of it is ejected (Why this does not fit)
Forty mL remains after systole, so the entire end-diastolic volume is not ejected.
B. EF is 60%, which establishes HFpEF without further evidence (Why this does not fit)
HFpEF requires a clinical syndrome with objective cardiac evidence, not preserved EF alone.
C. EF is 60%, but filling pressure and the cause of dyspnea still require assessment (Best answer)
The ejected fraction is (100 minus 40)/100; a preserved value cannot exclude high filling pressure.
D. EF is 40%, establishing HFrEF (Why this does not fit)
Forty percent is the residual end-systolic fraction; the ejected volume is 60 mL.
Takeaway: Calculate the fraction correctly, then ask a separate pressure question.
Raised left atrial and pulmonary venous pressures explain exertional dyspnea, orthopnea, paroxysmal nocturnal dyspnea and sometimes crackles. Supine redistribution of blood can worsen symptoms. Raised systemic venous pressure produces JVD, dependent edema, hepatic congestion and ascites. Right and left findings often coexist. Clear lungs do not exclude chronic HF, and JVD does not identify its cause. Left heart disease commonly produces secondary RV failure; cor pulmonale specifically arises from pulmonary or pulmonary vascular disease. [1][19]
History should establish time course, functional change, coronary symptoms, blood pressure, alcohol and cardiotoxic exposures, rhythm, family history and practical access to medicines. Examine perfusion and volume status. ECG, chest imaging, blood count, electrolytes, kidney function and echocardiography answer different questions. Echo assesses EF, valves, chamber geometry, RV function and filling indices. It cannot alone explain every patient's dyspnea. Ischemia can present without chest pain. [1][2]
Use natriuretic peptides in context
In acute dyspnea, BNP below 100 pg/mL or NT-proBNP below 300 pg/mL can make HF less likely; these are commonly used acute exclusion thresholds, not universal diagnostic boundaries. Age, AF and kidney dysfunction can increase concentrations. Obesity can suppress them, including in HFpEF. An intermediate or unexpectedly low result requires integration with the examination and imaging; selected uncertain cases need exercise testing or invasive filling-pressure assessment. [31][1][27]
Sacubitril inhibits neprilysin, so BNP may rise early after starting sacubitril/valsartan. NT-proBNP is not a neprilysin substrate and is less confusing during that period. Do not dismiss a rising BNP automatically: both markers retain prognostic value, and worsening symptoms still require evaluation. [9][10]
Stage describes disease history
A: risk factors without structural disease or HF symptoms. B: structural disease, abnormal filling pressure or qualifying biomarkers without current or prior HF symptoms. C: current or prior symptomatic HF. D: advanced symptoms that interfere with life and recur despite appropriate treatment.
NYHA class describes current limitation
I: ordinary activity is tolerated. II: ordinary activity produces symptoms. III: less than ordinary activity produces symptoms, with comfort at rest. IV: symptoms at rest or with any activity. Functional class can change with treatment.
A patient whose symptoms resolve remains stage C. Asymptomatic LV dysfunction is stage B and calls for prevention-focused treatment appropriate to its cause and EF, rather than automatic application of every symptomatic-HFrEF intervention. [1]
Do not stop at the syndrome label
Amyloid is suggested by disproportionate wall thickening, low ECG voltage, neuropathy or bilateral carpal tunnel disease. Begin the type assessment with serum free light chains and serum/urine immunofixation; a bone-tracer scan alone cannot safely exclude AL amyloidosis. HCM requires assessment of unexplained hypertrophy, systolic anterior mitral motion and dynamic outflow obstruction. Stress-associated apical dysfunction may be Takotsubo, but acute coronary disease and myocarditis must be evaluated. Coronary disease can coexist with Takotsubo. [15][16][17]
Build HFrEF therapy around complementary benefits
For symptomatic chronic HFrEF, establish the four tolerated foundational classes promptly. There is no requirement to maximize one before introducing the others. Loop diuretics relieve congestion alongside these treatments; relief of edema is not equivalent to proven survival benefit. Dose selection follows blood pressure, perfusion, kidney function, potassium and patient priorities. [1][2][28]
Four foundations and the decision that keeps each safe
The HF guideline advises against ARNI in patients with any history of angioedema; prior ACE inhibitor/ARB-related angioedema is also a labeled contraindication. ACE inhibitors, ARBs and ARNI are avoided in pregnancy because of fetal toxicity. Breastfeeding requires a separate drug-specific assessment; enalapril has very low milk exposure and can be used when needed. A dry ACE-inhibitor cough may prompt substitution, but hemoptysis or unexplained weight loss requires its own diagnostic workup. [29][10][14]
Interpret adverse effects before sacrificing benefit
Check kidney function and potassium after initiation or dose changes. A small asymptomatic renal change during effective decongestion does not automatically require stopping beneficial therapy. In CKD, KDIGO advises reassessment when creatinine increases by more than 30% within four weeks of starting or increasing an ACE inhibitor or ARB. Evaluate for volume depletion, NSAIDs, renovascular disease and other causes. A rise from 0.9 to 1.2 mg/dL is about 33%, not less than 30%. Symptomatic hypotension is a separate reason to reassess. [1][11]
Unexpected potassium of 5.8 mmol/L warrants prompt reassessment, medication review and repeat testing within three days or sooner according to clinical status. Illness, AKI, symptoms or ECG changes lower the threshold for urgent care. If potassium cannot be maintained below 5.5 on a steroidal MRA, discontinue it. Eplerenone can reduce spironolactone-associated gynecomastia, but it does not eliminate hyperkalemia risk. Severe hyperkalemia with ECG changes requires emergency membrane stabilization, potassium redistribution and elimination with monitoring. [1][13]
For orthostatic symptoms after marked fluid loss, reassess congestion and unnecessary blood-pressure-lowering drugs before reducing every foundation. A loop dose that was needed during edema may be excessive after decongestion. Fludrocortisone expands sodium and water stores and is contraindicated in HF; it is not a routine way to preserve a medication list. SGLT2-associated ketoacidosis can occur with modest glucose. Dapagliflozin should be withheld at least three days before major surgery or prolonged fasting and resumed when clinically stable with oral intake. [10][12][20]
Add treatment for a defined residual problem
Hydralazine plus isosorbide dinitrate is recommended for self-identified Black patients with persistent NYHA III/IV HFrEF on optimal therapy, and may be considered for patients unable to take RAAS-directed drugs regardless of race. Ivabradine targets sinus rhythm with resting rate ≥70/min in selected stable symptomatic patients with EF ≤35% despite maximally tolerated beta-blockade. It does not control AF. Digoxin may reduce HF hospitalization in selected persistent symptoms; it has not established a survival benefit and requires attention to kidney function, interactions and toxicity. [1][23][24]
Verapamil and diltiazem can worsen HFrEF through negative inotropy. Amlodipine may treat residual hypertension or angina without serving as a disease-modifying HF foundation. NSAIDs can cause sodium retention and renal dysfunction. The correct response to apparent treatment failure may be removal of an aggravating exposure or resolution of a prescription-access barrier. [1][2]
Treat preserved, mildly reduced and improved EF deliberately
HFpEF treatment begins with a confirmed syndrome, relief of congestion and identification of treatable contributors. Begin an SGLT2 inhibitor early when suitable, alongside exercise, weight management and treatment of hypertension, AF, kidney disease and ischemia. Lifestyle care should not become a reason to postpone effective medication. Beta-blockers need another indication, such as rate control or coronary disease; they are not universal HFpEF therapy. [3][7]
Finerenone, a nonsteroidal MRA, received a US indication in 2025 for HF with LVEF ≥40%. Consider it within current HFpEF care with potassium and kidney monitoring. Do not initiate if potassium exceeds 5.0 mmol/L or eGFR is below 25 mL/min/1.73 m². These thresholds differ from steroidal-MRA initiation criteria in HFrEF. Do not casually combine MRAs. The supporting benefit concerns HF events and a cardiovascular composite, not proof of a separate mortality reduction in every patient. [3][5]
For obesity-associated HFpEF, incretin-based treatment can improve weight and health status. SUMMIT found fewer cardiovascular-death-or-worsening-HF events with tirzepatide, driven by fewer worsening-HF events; it did not establish isolated cardiovascular mortality reduction. Discuss gastrointestinal effects, suitability and access. Selected patients may benefit from ARNI or ARB, particularly toward the lower preserved EF range. [3][6]
In HFmrEF, SGLT2 outcome evidence is stronger than simply assuming every HFrEF recommendation has identical support. Consider other therapies using the clinical phenotype, especially toward the lower EF range. HF with improved EF denotes improvement after previously reduced EF; symptomatic recovery is not proof that the disease is cured. Continue appropriate HFrEF therapy to reduce relapse risk. [1][4][7]
Try it here · Checkpoint 2 of 3
Make your prediction before reading the choices. A first attempt is just a starting point.
Case 21
Show answer and explanations for case 21
A. Ivabradine solely because he has HFpEF (Why this does not fit)
Its selected HFrEF indication is not established by preserved EF and no qualifying sinus-rate information.
B. Diltiazem as a proven universal HFpEF event-reducing foundation (Why this does not fit)
It may serve a selected rate/BP indication but does not have that universal disease-modifying role.
C. Finerenone with potassium and renal monitoring (Best answer)
The 2025 HF indication covers LVEF at least 40%, and his provided values meet initiation limits.
D. Routine chronic IV dobutamine for recurrent edema (Why this does not fit)
Inotropes are not routine therapy for a stable perfused patient with this phenotype.
Takeaway: Newer HFpEF options require their own EF, potassium and renal criteria.
IV loop diuresis and treatment of the trigger. Vasodilators may help when pressure permits.
Cold and congested
Hypoperfusion with excess filling pressure.
Urgent shock assessment, monitored circulatory support and individualized decongestion.
Cold without clear congestion
Determine whether filling is inadequate.
A cautious fluid trial is for an underfilled patient, not every low-output state.
Warm without congestion
No current overload or hypoperfusion.
Optimize chronic treatment and investigate other causes of symptoms.
Temperature terms describe clinical perfusion, not measured body temperature. Reassess blood pressure, mentation, urine output, extremities and congestion after treatment. [1][28]
Hypoxemic pulmonary edema may require oxygen and noninvasive ventilation. Severe hypertension can make rapid afterload reduction with IV nitrates useful when safe. Cardiogenic shock with hypotension and organ hypoperfusion requires critical care, treatment of the cause and selected vasopressor/inotrope or mechanical support. Do not initiate or increase beta-blockade in shock. Conversely, a stable, adequately perfused patient receiving IV diuresis does not automatically need an established beta-blocker stopped. [1][2]
Search for acute coronary disease, arrhythmia, infection, uncontrolled pressure, worsening valve disease and medication or access problems. Reassess renal function, electrolytes and urine response during decongestion. Nesiritide is not routine acute HF treatment: ASCEND-HF found no significant clinical outcome benefit and more hypotension, without a significant increase in its worsening-renal-function endpoint. [1][21][28]
Right-sided and pericardial emergencies need a different plan
Inferior infarction with hypotension, JVD and clear lungs suggests RV involvement; right-sided ECG leads and echo help. Arrange urgent reperfusion. Avoid nitrates in this hypotensive setting and consider cautious volume support only if filling is inadequate. This does not mean all chronic RV failure should receive fluid: a congested patient may need careful diuresis. Lung-related pulmonary hypertension requires treatment of the lung disorder, with oxygen when indicated; routine pulmonary arterial hypertension drugs are not established treatment for ordinary COPD-associated disease. [19][22]
Kussmaul sign is a rise or failure of the JVP to fall with inspiration, suggesting impaired right-sided filling, as in constriction, restriction or RV infarction. It is not a typical isolated tamponade finding. Tamponade is suggested by an effusion with hemodynamic compromise, pulsus paradoxus and right-sided chamber collapse on echo; urgent drainage treats the mechanical obstruction. Rapid accumulation of even a small effusion can cause tamponade, so size alone does not establish or exclude it. Constriction is a pericardial limitation with ventricular interdependence and often prominent systemic congestion. Distinguish both from intrinsic myocardial failure. [30][18][22]
Use electrical criteria and the patient's trajectory
An ICD prevents selected arrhythmic deaths; it does not directly correct filling pressure. A common primary-prevention indication is persistent EF ≤35%, NYHA II/III symptoms despite chronic optimized therapy and expected meaningful survival beyond one year. Reassess after a sufficient treatment period, commonly at least three months, with at least 40 days after MI and generally at least 90 days after revascularization before routine primary-prevention implantation. Selected ischemic patients with NYHA I and EF ≤30% also qualify. A low EF measured days after infarction is not enough for routine immediate primary-prevention implantation. [32][1]
CRT treats electrical dyssynchrony. The strongest standard pattern is EF ≤35%, sinus rhythm, LBBB with QRS ≥150 ms, and NYHA II/III or ambulatory IV symptoms despite therapy. Other patterns have more conditional indications; a narrow QRS does not justify conventional CRT solely because EF is low. Distinguish this from pacing for conduction disease. Mobitz II requires identifiable atrial activity with constant conducted PR intervals and intermittent failed conduction; AF cannot supply that PR pattern. Persistent acquired Mobitz II without a reversible cause warrants pacing assessment. [1][25]
Repeated admissions, progressive end-organ dysfunction, hypotension that limits therapy and severe symptoms despite treatment warrant an advanced-HF team. Consider transplantation or durable mechanical support in eligible patients, and integrate symptom-focused and palliative care according to goals. IV inotropes are selected bridge or palliative treatments, not an automatic consequence of NYHA IV. Follow-up must address tolerability, functional recovery, congestion and practical access as well as EF. [1][2]
Try it here · Checkpoint 3 of 3
Make your prediction before reading the choices. A first attempt is just a starting point.
Case 31
Show answer and explanations for case 31
A. ICD shock therapy alone (Why this does not fit)
An ICD treats malignant arrhythmias but does not by itself provide resynchronization.
B. CRT assessment, including whether a defibrillator component is appropriate (Best answer)
The combination of persistent low EF, symptoms, sinus rhythm and wide LBBB fits a strong CRT indication.
C. A standard single-chamber RV pacemaker solely to correct the LBBB and restore ventricular synchrony (Why this does not fit)
Conventional RV-only pacing is not equivalent to CRT and can add ventricular dyssynchrony.
D. Ivabradine solely because the QRS is wide (Why this does not fit)
Ivabradine selection depends on qualifying sinus rate and other criteria, not QRS width.
Takeaway: The electrical pattern adds information that EF alone cannot supply.
A. NT-proBNP falls because neprilysin directly degrades it, so a decrease proves the biomarker is no longer interpretable during ARNI therapy (Why this does not fit)
NT-proBNP is not a neprilysin substrate.
B. Early neprilysin inhibition can increase BNP; interpret the trend with clinical status and NT-proBNP (Best answer)
The divergent biomarkers can occur during beneficial treatment, without making every future BNP rise benign.
C. The BNP result establishes recurrent pulmonary edema (Why this does not fit)
Clinical improvement and the drug effect make that conclusion unsupported.
D. Both tests are permanently unusable during ARNI treatment (Why this does not fit)
Both retain prognostic value; early interpretation differs.
Takeaway: ARNI changes early BNP interpretation, not the need to assess the patient.
A. Apply HFrEF four-class therapy solely because the RV is dilated (Why this does not fit)
Evidence for symptomatic LV HFrEF cannot automatically be transferred to this cause of RV failure.
B. Optimize lung disease, provide oxygen when indicated and manage congestion carefully (Best answer)
Treatment targets the pulmonary driver and the RV volume burden, with specialist assessment for severe or uncertain disease.
C. Routine sildenafil for all COPD-associated pulmonary hypertension regardless of lung disease severity or oxygen need (Why this does not fit)
PAH-directed treatment is not routine therapy for group 3 COPD-associated disease.
D. Avoid diuretics despite edema to preserve RV preload (Why this does not fit)
Some acute underfilled RV states need cautious fluid, but this patient is systemically congested. Carefully monitored decongestion can be appropriate while treating the lung disease.
Takeaway: Cor pulmonale calls for treatment of the pulmonary cause.
A. Review potassium sources and interacting drugs, adjust or hold the MRA as appropriate, and repeat promptly within three days or sooner (Best answer)
This addresses a potentially progressive adverse effect while tailoring urgency to stability and renal status.
B. Leave the dose unchanged and check at a routine visit in six weeks (Why this does not fit)
An unexpected new increase requires a much earlier safety assessment.
C. Administer emergency IV calcium solely because potassium is 5.8 with a normal ECG, then discharge without reviewing the MRA or arranging earlier repeat testing (Why this does not fit)
Calcium is for cardiac membrane stabilization in appropriate emergency settings; the presented stable result calls for prompt assessment rather than this automatic intervention.
D. Replace spironolactone with the same dose of eplerenone and omit repeat testing (Why this does not fit)
Changing steroidal MRAs does not remove hyperkalemia risk.
Takeaway: Unexpected hyperkalemia needs a specific early follow-up plan.
A. Stop the supplement and arrange an outpatient test next week (Why this does not fit)
Severe hyperkalemia with ECG changes poses an immediate arrhythmic risk.
B. Provide monitored emergency treatment including IV calcium and insulin with glucose, while planning potassium elimination and treating AKI (Best answer)
Calcium stabilizes the myocardium; redistribution and elimination address potassium, with glucose monitoring and reassessment.
C. Treat only with an oral potassium binder and discharge when it is swallowed (Why this does not fit)
Potassium elimination alone is too slow to address immediate cardiac toxicity without monitoring and acute treatment.
D. Switch spironolactone to eplerenone before treating the ECG change (Why this does not fit)
The alternative also retains potassium and does not treat acute electrical toxicity.
Takeaway: Treat severe hyperkalemic electrical toxicity immediately.
A. The result proves irreversible ACE-inhibitor nephrotoxicity (Why this does not fit)
Volume depletion and hemodynamic changes are plausible reversible causes.
B. The drug must be permanently prohibited regardless of recovery because any creatinine rise after initiation proves irreversible toxicity (Why this does not fit)
Temporary adjustment and correction of contributing causes may permit later use.
C. The rise is about 33%; assess volume depletion, pressure and medications and adjust treatment as needed (Best answer)
The increase exceeds the KDIGO CKD threshold of more than 30% within four weeks and accompanies a convincing hypovolemic history.
D. The rise is 25%, so no assessment is needed (Why this does not fit)
The change is divided by the baseline 0.9, giving about 33%, and symptoms independently matter.
Takeaway: Correct arithmetic and symptoms both guide renal-safety decisions.
A. It proved an isolated cardiovascular mortality reduction in all HF phenotypes (Why this does not fit)
The trial studied obesity with HFpEF and did not establish a separate cardiovascular death benefit.
B. It showed weight loss but measured no clinical HF events (Why this does not fit)
Clinical HF events were part of the primary outcome.
C. It established that diuretics and SGLT2 inhibitors should be stopped when tirzepatide starts (Why this does not fit)
The trial does not justify discarding otherwise appropriate HF care.
D. It reduced a composite of cardiovascular death or worsening HF and improved health status; the event benefit was driven by worsening HF (Best answer)
This distinguishes the demonstrated outcome from an unsupported standalone mortality claim.
Takeaway: Name the demonstrated endpoint when counseling about benefit.
A. Optimize therapy and reassess after the relevant post-MI and post-revascularization intervals (Best answer)
Recovery and treatment response must be considered; routine implantation is not indicated at day ten.
B. Decide from the acute EF alone that no reassessment is needed after recovery, revascularization or optimized medical therapy (Why this does not fit)
Both recovery and persistent dysfunction are possible; later EF, symptoms and treatment response determine eligibility.
C. Implant CRT now despite a QRS of 98 ms (Why this does not fit)
Neither the electrical pattern nor the early timeline supports routine CRT.
D. Implant now solely because the discharge EF is below 35% (Why this does not fit)
Early post-MI EF does not bypass waiting and reassessment requirements.
Takeaway: Distinguish a low early EF from persistent primary-prevention eligibility.
A. Double it immediately before congestion is relieved (Why this does not fit)
Initiation or upward titration is generally deferred until compensated.
B. Stop it solely because an IV diuretic was required during hospitalization, even with preserved perfusion and stable blood pressure (Why this does not fit)
Hospitalization or loop route alone is not a contraindication.
C. Continue the established dose unless a specific contraindication develops (Best answer)
Congestion with adequate perfusion does not automatically require withdrawal of preexisting therapy.
D. Replace it with dobutamine despite adequate perfusion (Why this does not fit)
There is no shock or low-output indication for routine inotropic support here.
Takeaway: Continuation during stable decongestion differs from initiation during instability.
A. Give repeated large fluid loads regardless of response (Why this does not fit)
RV overdistention can also impair output; any volume trial requires reassessment.
B. Avoid nitrates and consider cautious volume support if assessment shows inadequate filling (Best answer)
Support RV preload judiciously while prioritizing reperfusion, with ongoing hemodynamic assessment.
C. Give sublingual nitroglycerin despite hypotension (Why this does not fit)
Further preload and pressure reduction can worsen RV infarct shock.
D. Treat this as isolated LV pulmonary edema with aggressive diuresis despite clear lungs, hypotension and evidence of RV infarction (Why this does not fit)
The clear lungs and right-sided ECG support RV involvement, and no pulmonary overload is described.
Takeaway: RV infarct shock requires a preload-aware plan, not automatic nitrate use.
A. Pure left-sided systolic failure established by JVD alone (Why this does not fit)
JVD does not establish LV systolic dysfunction, and the respiratory findings favor constriction.
B. Isolated uncomplicated cardiac tamponade (Why this does not fit)
The imaging shows no effusion or chamber collapse and instead demonstrates respiratory ventricular interdependence. Kussmaul sign is not typical of isolated tamponade. Small rapidly accumulating effusions can cause tamponade, so size alone would not exclude it.
C. Constrictive pericarditis (Best answer)
Systemic congestion, Kussmaul sign and respiratory ventricular interdependence support pericardial constriction.
D. Isolated dependent venous edema (Why this does not fit)
That would not account for the raised central venous pressure and cardiac imaging findings.
Takeaway: Interpret Kussmaul sign with respiratory imaging rather than as a generic HF sign.
