The absence of which of the following makes a diagnosis of pulmonary embolism unlikely?

Ans-CRef: Harrison's Principles of Internal Medicine, 18ed. Chapter 262. Deep Venous Thrombosis and Pulmonary Thromboembolism. PgExplanation:"Dyspnea is the most common symptom of Pulmonary embolism, and tachypnea is the most common sign "Pulmonary embolism Predisposing factors for pulmonary embolism are:Prothrombotic states: Mutant factor V Leiden, deficiency of antithrombin, protein C & S, hyperhomocysteinemia, APLA, OC pills, pregnancy, cancer, surgery, trauma, bed-ridden patient, long-air travel. COPDPathophysiology:Hypoxemia, increased alveolar-arterial gradient, increased pulmonary vascular & airway resistanceImpaired gas exchange, alveolar hyperventilation, decreased pulmonary complianceSymptoms - massive VTE- sudden hypotension, moderate: RV hypokinesia on ECHOPleuritic chest pain- small, peripheral infarction,Unexplained breathlessness- MC symptom, tachypnea -MC signNonthrombotic PE- fat, air, amniotic fluid, cement, hair, talc, cottonTests:D-Dimer assay- sensitive 'rule out' testFalse positive in MI, pneumonia, sepsis, cancer, pregnancy, post-op stateABG- low pO2 & pCO2, high A-a gradientS.troponin. heart-type fatty acid binding protein, BNP, NT-pro BNP) due to RV microinfarctionECG:Sinus tachycardiaAcute right axis deviationRBBBS1Q3TS signT-wave inversion in V1-V4CXR:Hampton's sign-peripheral wedge-shaped density above the diaphragm.Wester mark's sign - focal oligemia.Falla's sign- enlarged right pulmonary arteryECHO- McConnell's sign- Hypokinesia of RV free wall, normal RV apexMultidetector-row spiral CT- Very sensitive, noninvasive testPulmonary angiography -- Gold standard Test (Most specific)Treatment:UFH/LMWH /Fondaparinux/WarfarinNovel anticoagulants- DTI-Argatroban, lepirudin, bivalirudin: Factor Xa inhibitor- RivaroxabanFibrinolysis with t-PA dissolves thrombus prevents serotonin release, prevents recurrence of PE by lysing source of thrombusEmbolectomyPrevention:High-risk surgery, total hip replacement, medical illness, long-term bedridden patientMini - UFH/LMWH/fondaparinux/IPC/rivaroxaban/dalteparinFor 4-5 WksIVC fillets