A 32-year-old male was diagnosed with achalasia cardia. High-resolution manometry revealed massive, simultaneous, high-pressure contractions of the distal oesophagus. According to the Chicago classification, the patient has which type of achalasia?

Explanation

## Correct Answer: A. Type Ill The Chicago classification (2011) is the gold standard for manometric phenotyping of achalasia based on high-resolution manometry (HRM) findings. Type III achalasia is characterized by **premature contractions** (also called spastic contractions) with simultaneous, high-amplitude, high-pressure distal oesophageal contractions occurring within 4.5 seconds of the swallow. These are rapid-onset, repetitive contractions that distinguish it from other types. The key discriminator is the presence of **≥20% premature (spastic) contractions** in the distal oesophagus combined with elevated integrated relaxation pressure (IRP) at the lower oesophageal sphincter (LOS). The clinical presentation often includes severe dysphagia and chest pain, mimicking cardiac ischemia. In Indian practice, HRM is increasingly available in tertiary centres, and Type III achalasia typically shows worse prognosis with medical therapy alone, often requiring more aggressive intervention (pneumatic dilation or POEM). The simultaneous, high-pressure contractions described in this case are pathognomonic for Type III, distinguishing it from Type I (absent contractility) and Type II (panesophageal pressurization). ## Why the other options are wrong **B. Type I** — Type I achalasia is characterized by **absent distal oesophageal contractions** (aperistalsis) with elevated IRP. There are no simultaneous high-pressure contractions; instead, the distal oesophagus shows minimal or no peristaltic activity. This is the most common type (~60% of achalasia cases) and typically has better prognosis with pneumatic dilation. The presence of massive simultaneous contractions rules out Type I. **C. Type II** — Type II achalasia shows **panesophageal pressurization** (compression waves) with elevated IRP but preserved some distal contractions. The contractions are not as rapid or spastic as Type III. Type II typically has intermediate prognosis and responds better to pneumatic dilation than Type III. The description of 'massive, simultaneous, high-pressure' spastic contractions is not characteristic of Type II's pressurization pattern. **D. Type IV** — Type IV achalasia (also called 'diffuse esophageal spasm with achalasia') is not a standard Chicago classification category for achalasia. The Chicago classification includes only Types I, II, and III. Type IV was used in older classification systems but has been abandoned. Confusion with diffuse esophageal spasm (DES) may occur, but DES is a separate motility disorder with normal LOS relaxation. ## High-Yield Facts - **Chicago Classification Type III achalasia**: ≥20% premature (spastic) contractions in distal oesophagus with elevated IRP (>15 mmHg). - **Type III clinical features**: Severe dysphagia, chest pain, rapid symptom onset; worst prognosis with medical therapy; requires pneumatic dilation or POEM. - **Type I (60% of cases)**: Absent distal contractions + elevated IRP; best response to pneumatic dilation. - **Type II (30% of cases)**: Panesophageal pressurization + elevated IRP; intermediate prognosis. - **HRM interpretation**: Integrated Relaxation Pressure (IRP) >15 mmHg at LOS is diagnostic threshold for all achalasia types; phenotype determined by distal oesophageal contractility pattern. ## Mnemonics **Chicago Achalasia Types (by contractility)** Type I = **I**nert (no contractions) | Type II = **II**nflated (pressurization) | Type III = **III**ritable (spastic/premature contractions). Use when classifying HRM findings. **Type III Red Flags** **SPASM**: Spastic contractions, Premature onset, Amplitude high, Severe symptoms, Aggressive disease, Manometry shows ≥20% abnormal. Mnemonic for remembering Type III's aggressive phenotype. ## NBE Trap NBE may conflate "high-pressure contractions" with "normal peristalsis" and lure students toward Type II (panesophageal pressurization). The key trap is distinguishing **spastic/premature contractions** (Type III) from **pressurization waves** (Type II)—both appear as elevated pressure, but Type III has rapid, repetitive spastic onset within 4.5 seconds of swallow. ## Clinical Pearl In Indian tertiary centres, Type III achalasia patients often present with severe, refractory dysphagia and atypical chest pain, leading to unnecessary cardiac workup. Recognition of the spastic phenotype on HRM guides early referral for pneumatic dilation or POEM rather than prolonged medical therapy, improving outcomes and reducing morbidity. _Reference: Bailey & Love Ch. 27 (Oesophagus); Harrison Ch. 286 (Disorders of Oesophageal Motility); Robbins Ch. 15 (GI Pathology)_