A dramatic ST-elevation ECG in the ICU.

Acute STEMI?
Not always.
An important ECG mimic every clinician should recognize: the shark fin pattern. 🧵🧵🧵 A 54-year-old woman was admitted with septic shock secondary to an intra-abdominal infection.

On presentation:
- Temperature: 38.6°C
- BP: 82/56 mmHg
- HR: 109 bpm
- RR: 26/min

Cardiac biomarkers:
- Troponin I: 2.02 ng/mL
- NT-proBNP: 5300 pg/mL

Aortic Stenosis (AS): essential clinical pearls every clinician should know🧵 🧵 🧵
A concise thread on pathophysiology, diagnosis, prognosis, and management.

1/ Aortic stenosis is a progressive valvular disease causing obstruction to left ventricular outflow. 2/ Main causes of AS:
🔵 Degenerative calcific disease remains the leading cause in older adults.
🔵Bicuspid aortic valve is the most common cause in younger patients
🔵Rheumatic disease remains an important cause in developing regions.

Right Ventricular (RV) Infarction: A Must-Know ECG Pattern.

RV infarction often coexists with inferior MI but is frequently overlooked. Missing it can be dangerous, as treatment differs from LV infarcts!

Here’s how to detect it on ECG ⬇️ 1️⃣ When to Suspect RV Infarction?
🔹 Any inferior MI (ST ↑ in II, III, aVF)
🔹 Hypotension + JVD + clear lungs
🔹 Bradycardia, AV block

A simple rule that works well in practice: inferior MI + hypotension = look for RV involvement

Abdominal aortic aneurysm (AAA) is one of the most dangerous silent conditions in medicine.
Most patients don’t know they have it.
Many never get a second chance once it presents.
🧵 1/
An AAA is a localized dilation of the abdominal aorta, reaching at least 150% of its normal diameter.
It sounds simple, but the implication is serious:
as the vessel enlarges, the wall weakens, and rupture becomes inevitable if it progresses.

Interpreting an #ECG can seem overwhelming at first, but with a structured approach, it becomes far more manageable.

In this thread, I’ll walk you through how to analyze an ECG like a professional, step by step.

Let’s begin.🧵 Step 0: Initial Checks
1. Paper Speed
The standard ECG paper speed is 25 mm/s, meaning:
◾1 small square = 0.04 s
◾1 large square = 0.20 s (5 small squares)
2. Calibration
This determines the amplitude of the waves:
⏺️ 1 mV = 10 mm (i.e., 2 large squares vertically.

Acute coronary syndrome management extends far beyond revascularization.

Optimal outcomes depend on a structured, evidence-based strategy before, during, and after intervention.
A concise summary of the 2025 guideline approach: 🧵 1/
Dual antiplatelet therapy (DAPT) remains foundational in ACS.
In patients undergoing PCI, ticagrelor or prasugrel is preferred over clopidogrel due to superior ischemic protection.

The new 2026 stroke guidelines quietly changed several things about acute stroke care.

Some patients should now go directly to thrombectomy centers.
Tenecteplase is gaining ground.
And aggressive BP control may actually harm patients.

Here’s what changed. 🧵 1/
Stroke care now starts before the patient even reaches the hospital.
Mobile Stroke Units are gaining strong support.
These ambulances carry CT scanners and stroke teams, allowing rapid diagnosis and thrombolysis in the field.

🚨 The 2026 dyslipidemia guideline just dropped, and it quietly changes how we think about cholesterol risk.
Here are 10 takeaways clinicians shouldn’t ignore 🧵 1️⃣ Start earlier.
Atherosclerosis begins young. Lifestyle counseling should start in youth, and pharmacotherapy may be needed early in familial hypercholesterolemia or when LDL-C ≥160 mg/dL.

1/
Most people think you need an angiogram to detect coronary artery disease.

But sometimes, the first clue appears on a simple echocardiogram.

Here are echo findings that quietly reveal coronary artery disease (CAD), even before other tests. 🧵 2/
In CAD, the first thing echo helps us look for is regional wall motion abnormalities.
When a coronary artery can't deliver enough blood, the affected myocardial segment stops contracting normally.
This is often the earliest visible sign of ischemia.

Why ST Elevation Isn’t Always a STEMI.

Every clinician has felt that moment…

You see an ST elevation on #ECG and your heart rate goes up before the patient’s does. STEMI? Cath lab activation? Thrombolysis?

But here’s the reality:
Not every ST elevation means ACS
A 🧵 1️⃣ Acute Coronary Occlusion (STEMI)

The classic cause. When a coronary artery is blocked, transmural myocardial ischemia develops and the ST segment elevates.

Time = muscle.
Reperfusion therapy (PCI or thrombolysis) has the greatest benefit when done early.

Palpitations, syncope, unexplained arrhythmias: which cardiac monitor should you choose?
A short guide to the most commonly used ambulatory ECG monitoring devices and when to use them. 🧵 1/ Holter Monitor
A portable ECG device that records continuously for 24–72 hours (up to ~2 weeks in newer models).
Patients can mark symptoms using an event button or diary to correlate symptoms with rhythm.
Best for frequent symptoms expected to occur within a few days.

🧵 Why can oxygen worsen respiratory failure in COPD?
Many clinicians still fear giving oxygen to COPD patients.
The reason they’re taught?
"Loss of hypoxic drive"
But this is mostly a myth.
Here’s what really causes oxygen-induced hypercapnia 👇 Oxygen does NOT usually cause dangerous hypercapnia by stopping breathing.
Studies show:
- Ventilatory drive remains high
- Minute ventilation recovers quickly
- CO₂ continues to rise anyway
So what’s the real mechanism?

High blood pressure is often called the "silent killer."
Yet it remains the most common modifiable risk factor for heart disease and stroke worldwide.
Here are the key takeaways from the 2025 ACC/AHA Hypertension Guideline every clinician should know. 🧵 1/
High blood pressure remains the most common modifiable risk factor for cardiovascular disease.
It contributes to coronary artery disease, HF, stroke, atrial fibrillation, dementia, CKD and premature death.

The general treatment goal for adults: <130/80 mm Hg.

Interpreting an #ECG can seem overwhelming at first, but with a structured approach, it becomes far more manageable.

In this thread, I’ll walk you through how to analyze an ECG like a professional, step by step.

Let’s begin.🧵 Step 0: Initial Checks
1. Paper Speed
The standard ECG paper speed is 25 mm/s, meaning:
◾1 small square = 0.04 s
◾1 large square = 0.20 s (5 small squares)
2. Calibration
This determines the amplitude of the waves:
⏺️ 1 mV = 10 mm (i.e., 2 large squares vertically

🧵 Thread: Brugada-type ECG, beyond the classic Type 1 pattern
1/
Brugada syndrome is defined by dynamic ECG changes in the right precordial leads (V1–V3), not a single static pattern.
Understanding when and why these patterns appear is as important as recognizing them. 2/
Consensus classification describes three Brugada-type ECG patterns based on ST-segment morphology and J-point amplitude:
🟢 Type 1 (coved)
🟢 Type 2/3 (saddleback spectrum)
🟢Type S (mild coved, “suggestive”)
📌 Only Type 1 is diagnostic.

2026 Stroke Guideline: 10 Updates You MUST Know
The 2026 AHA/ASA Acute Ischemic Stroke Guideline just dropped and it changes practice.
Here are the 10 most important updates 🧵⬇️ 1️⃣ Mobile Stroke Units (MSUs)
MSUs are recommended where available because they significantly reduce onset-to-thrombolysis time and improve outcomes.

Speed still saves brain 🧠

🧵 Why can oxygen worsen respiratory failure in COPD?
Many clinicians still fear giving oxygen to COPD patients.
The reason they’re taught?
"Loss of hypoxic drive"
But this is mostly a myth.
Here’s what really causes oxygen-induced hypercapnia 👇 Oxygen does NOT usually cause dangerous hypercapnia by stopping breathing.
Studies show:
- Ventilatory drive remains high
- Minute ventilation recovers quickly
- CO₂ continues to rise anyway
So what’s the real mechanism?

The Liver Speaks Through the Body

The liver rarely complains out loud but it leaves clues everywhere. From yellowing eyes and reddened palms to distended abdomens and subtle nail changes, liver disease tells its story on the skin, breath, and body.
A 🧵 🔵Icterus
Yellow discoloration of the sclera caused by elevated serum bilirubin. It reflects impaired bilirubin metabolism or excretion and is often the earliest visible sign of liver dysfunction.

Activate the Cath Lab: ECG patterns that matter even without classic STEMI
Not every coronary occlusion announces itself with obvious ST-segment elevation.
Some ECG patterns are quieter, atypical, and easy to miss, yet they represent the same emergency.
Thread below ⬇️ 🔵 Posterior MI & Right Ventricular MI
Posterior infarction often presents as ST depression in V1–V3 with tall R waves.
Posterior leads (V7–V9) may reveal the missing ST ⬆️.
RV infarction shows ST⬆️ in right-sided leads (V3R–V4R)
Both require urgent reperfusion.

What Makes V1–V3 Unique?
Although every ECG should be read systematically, V1–V3 deserve special attention because they capture patterns that may remain subtle or even invisible in other leads. Their position over the RV, septum, and RVOT gives them unique diagnostic value
A 🧵 🔵Early Anterior Ischemia
These leads are the earliest to show anterior ischemia. Subtle hyperacute T waves, loss of R-wave progression, ST elevation, and the de Winter pattern often appear in V2–V3 long before other leads show convincing changes.

Why ST Elevation Isn’t Always a STEMI.

Every clinician has felt that moment…

You see an ST elevation on #ECG and your heart rate goes up before the patient’s does. STEMI? Cath lab activation? Thrombolysis?

But here’s the reality:
Not every ST elevation means ACS
A 🧵 1️⃣ Acute Coronary Occlusion (STEMI)

The classic cause. When a coronary artery is blocked, transmural myocardial ischemia develops and the ST segment elevates.

Time = muscle.
Reperfusion therapy (PCI or thrombolysis) has greatest benefit when done early.