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Surgical sieve
💓 Tachycardia
ECG first: narrow or broad, regular or irregular? Then ask whether the heart is the problem or is compensating for one — because slowing a compensatory tachycardia is how you arrest someone.
| Ventricular tachycardia Must exclude | Broad complex, regular, rate 120–250. Assume VT in any broad complex tachycardia, especially with known ischaemic heart disease — it is the safe assumption, not the clever one.Adverse features (shock, syncope, ischaemia, heart failure) mean synchronised DC cardioversion, not drugs. |
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| Massive PE Must exclude | Sinus tachycardia with hypoxia and a clear chest. The commonest ECG finding is sinus tachycardia, not S1Q3T3.Wells, then CTPA. Bedside echo if too unstable to travel. |
| Sepsis (any source) Must exclude | Tachycardia is often the earliest and sometimes the only abnormal observation. Fever may be absent, and hypothermia is worse.Sepsis Six within the hour. A persistent unexplained tachycardia in an inpatient is a septic screen. |
| GI bleed Must exclude | Tachycardia precedes hypotension by a long way, particularly in the young. A normal blood pressure with a rate of 120 is a compensating patient, not a stable one.Two large cannulae, group and save, PR examination. |
| Anaphylaxis Must exclude | Tachycardia with hypotension after a drug, blood product or contrast, usually with skin or airway signs.IM adrenaline 500 micrograms. |
| Atrial fibrillation with rapid ventricular rate Time-sensitive | Irregularly irregular, narrow complex. Look for the cause — sepsis, PE, alcohol, thyrotoxicosis, electrolytes, pain — because treating the rate without the cause usually fails.Rate control if stable and the onset is not clearly under 48 hours. Adverse features mean cardioversion. |
| Supraventricular tachycardia Time-sensitive | Narrow, regular, around 150, with an abrupt start and stop. Younger patients, often no cardiac history.Valsalva — the modified version with leg raise works far better — then adenosine with continuous ECG. Warn the patient how adenosine feels. |
| Hypovolaemia / pre-renal Time-sensitive | Dry, oliguric, poor intake, diuretics, vomiting. The tachycardia IS the compensation — this is the one where a beta-blocker is dangerous.Fluid challenge and reassess the rate. If the rate falls, you have your answer. |
| Thyroid storm Time-sensitive | Tachycardia or AF out of proportion, with fever, agitation, tremor and often diarrhoea. Precipitated by infection, surgery, iodinated contrast or stopping antithyroid drugs.Burch-Wartofsky. Order matters: thionamide BEFORE iodine, and beta-blockade for the symptoms. |
| Alcohol withdrawal Time-sensitive | Tachycardia, tremor, sweating and agitation, classically on day 2 to 3 of an admission nobody realised was also a detox.CIWA-guided benzodiazepine and parenteral thiamine BEFORE any glucose. Seizures and delirium tremens are the things to prevent. |
| Pain Common | Uncontrolled pain, urinary retention or a full bladder will hold a rate at 110 indefinitely. Look at the patient and at the drug chart before the monitor.Treat the pain, scan the bladder, then reassess the rate. |
| Drug toxicity or withdrawal Time-sensitive | Salbutamol, aminophylline, inotropes, anticholinergics, cocaine and amphetamines cause it; so does missing a regular beta-blocker.Read the chart including what was STOPPED. Beta-blocker rebound is real. |
| Anaemia Common | Compensatory sinus tachycardia, often with exertional breathlessness. Chronic anaemia tolerates remarkably low haemoglobins with a fast heart.FBC, and a cause. Transfusing without asking why is treating the number. |
| Hyperventilation / anxiety Consider | Paraesthesia, carpopedal spasm, a normal examination and normal observations otherwise. Common, and never the first answer in a new tachycardia.A diagnosis of exclusion. Check the observations and the ECG before you accept it. |
| Measurement or monitoring artefact Consider | A monitor counting T waves or artefact as beats, a shivering patient, or a lead that has come off. Compare the monitor with the pulse at the wrist.Feel the pulse. A rate of 240 in a comfortable patient talking to you deserves a manual check before treatment. |
15 differentials · 10 open a full pathway in the app.