Hypertensive heart disease
How a ventricle pumping against high pressure thickens (Laplace), why the thick wall fills poorly, enlarges the atrium and runs short of oxygen, how it can finally dilate, and how lung disease does the same to the right ventricle.
By the end, you can
- Use the law of Laplace to explain why a pressure load produces concentric hypertrophy and a dilated ventricle has a high wall stress.
- Explain how hypertrophy and fibrosis impair relaxation and filling, and why this enlarges the left atrium and favours atrial fibrillation.
- Explain why hypertrophied muscle becomes ischaemic even with normal coronary arteries.
- Describe how compensated concentric hypertrophy can progress to a dilated, failing ventricle, and relate cor pulmonale to the same process on the right.
- Recognise the morphology, ECG and echocardiographic criteria and differentials of hypertensive heart disease, and explain how treatment acts on its mechanism.
What it is
Hypertensive heart disease is the change in the heart caused by long-standing systemic hypertension: left ventricular hypertrophy, usually concentric, with impaired filling, left atrial enlargement, ischaemia of the thickened muscle and, in some people, later dilatation and heart failure. It is diagnosed when hypertrophy accompanies hypertension and no other cause explains it. Cor pulmonale is the right-sided counterpart: right ventricular hypertrophy or dilatation from pulmonary hypertension caused by disease of the lungs or their vessels.
4 types to tell apart
- Compensated concentric hypertrophy
- A thick wall round a normal or small cavity, with normal wall stress and ejection fraction; often silent, apart from impaired relaxation.
- Heart failure with preserved ejection fraction
- The stiff, thick ventricle fills only at a high pressure, congesting the lungs although it empties normally.
- Dilated (decompensated) hypertensive heart
- After years of overload, muscle loss and fibrosis let the ventricle dilate and its contraction weaken (heart failure with reduced ejection fraction).
- Cor pulmonale
- Chronic (hypertrophy from slowly rising pulmonary pressure, usually lung disease) or acute (sudden dilatation, as after a large pulmonary embolus).
US spelling: ischaemia → ischemia, fibre → fiber.
Normal function
How the left ventricle carries its load
The ejects against the systemic arterial pressure, about five times the pressure the meets in the lungs, and its wall is about three times thicker. That pressure, the afterload, is the main load it carries in systole.
How hard each muscle fibre must pull is set by the wall stress, described by the law of Laplace: stress is roughly pressure × cavity radius ÷ (2 × wall thickness). A higher pressure or a larger cavity raises the stress on every fibre; a thicker wall shares it among more muscle. Wall stress is a main driver of the muscle’s oxygen demand.
Filling needs different properties: in diastole the muscle must relax actively, pumping calcium back into its stores, and the wall must be compliant so that the ventricle fills at a low pressure. The belongs to both ventricles and moves with whichever side has the higher pressure.
Underlying change · Step 1 of 5
Pressure overload: concentric hypertrophy
The full lesson is part of Student Pro
It takes you through all 5 steps of the mechanism, explains the symptoms, signs and findings each step causes, adds the exam detail and how treatment works where the lesson has them, then recaps it and lets you check yourself with 10 self-check questions. The full pathophysiology library: guided lessons with self-check questions comes with Student Pro, with 100 tutor answers a month and the full available catalogue.
Free to read: the introduction and .
Disrupted function · Step 2 of 5
A stiff ventricle: high filling pressure, a big atrium and atrial fibrillation
The full lesson is part of Student Pro
It takes you through all 5 steps of the mechanism, explains the symptoms, signs and findings each step causes, adds the exam detail and how treatment works where the lesson has them, then recaps it and lets you check yourself with 10 self-check questions. The full pathophysiology library: guided lessons with self-check questions comes with Student Pro, with 100 tutor answers a month and the full available catalogue.
Free to read: the introduction and .
Disrupted function · Step 3 of 5
Thick muscle outgrows its blood supply
The full lesson is part of Student Pro
It takes you through all 5 steps of the mechanism, explains the symptoms, signs and findings each step causes, adds the exam detail and how treatment works where the lesson has them, then recaps it and lets you check yourself with 10 self-check questions. The full pathophysiology library: guided lessons with self-check questions comes with Student Pro, with 100 tutor answers a month and the full available catalogue.
Free to read: the introduction and .
Consequences · Step 4 of 5
From a thick to a dilated ventricle
The full lesson is part of Student Pro
It takes you through all 5 steps of the mechanism, explains the symptoms, signs and findings each step causes, adds the exam detail and how treatment works where the lesson has them, then recaps it and lets you check yourself with 10 self-check questions. The full pathophysiology library: guided lessons with self-check questions comes with Student Pro, with 100 tutor answers a month and the full available catalogue.
Free to read: the introduction and .
Consequences · Step 5 of 5
The right-sided counterpart: cor pulmonale
The full lesson is part of Student Pro
It takes you through all 5 steps of the mechanism, explains the symptoms, signs and findings each step causes, adds the exam detail and how treatment works where the lesson has them, then recaps it and lets you check yourself with 10 self-check questions. The full pathophysiology library: guided lessons with self-check questions comes with Student Pro, with 100 tutor answers a month and the full available catalogue.
Free to read: the introduction and .
Symptoms and signs
Symptoms, signs and findings
The full lesson is part of Student Pro
It takes you through all 5 steps of the mechanism, explains the symptoms, signs and findings each step causes, adds the exam detail and how treatment works where the lesson has them, then recaps it and lets you check yourself with 10 self-check questions. The full pathophysiology library: guided lessons with self-check questions comes with Student Pro, with 100 tutor answers a month and the full available catalogue.
Free to read: the introduction and .
Exam detail
Exam detail
The full lesson is part of Student Pro
It takes you through all 5 steps of the mechanism, explains the symptoms, signs and findings each step causes, adds the exam detail and how treatment works where the lesson has them, then recaps it and lets you check yourself with 10 self-check questions. The full pathophysiology library: guided lessons with self-check questions comes with Student Pro, with 100 tutor answers a month and the full available catalogue.
Free to read: the introduction and .
Treatment
How treatment works
The full lesson is part of Student Pro
It takes you through all 5 steps of the mechanism, explains the symptoms, signs and findings each step causes, adds the exam detail and how treatment works where the lesson has them, then recaps it and lets you check yourself with 10 self-check questions. The full pathophysiology library: guided lessons with self-check questions comes with Student Pro, with 100 tutor answers a month and the full available catalogue.
Free to read: the introduction and .
Recap
Recap
The full lesson is part of Student Pro
It takes you through all 5 steps of the mechanism, explains the symptoms, signs and findings each step causes, adds the exam detail and how treatment works where the lesson has them, then recaps it and lets you check yourself with 10 self-check questions. The full pathophysiology library: guided lessons with self-check questions comes with Student Pro, with 100 tutor answers a month and the full available catalogue.
Free to read: the introduction and .
Self-check
Check your understanding
The full lesson is part of Student Pro
It takes you through all 5 steps of the mechanism, explains the symptoms, signs and findings each step causes, adds the exam detail and how treatment works where the lesson has them, then recaps it and lets you check yourself with 10 self-check questions. The full pathophysiology library: guided lessons with self-check questions comes with Student Pro, with 100 tutor answers a month and the full available catalogue.
Free to read: the introduction and .