ABC-AF Bleeding Score ABC-AF Stroke Score ABCD2 Score ADD-RS Aortic Valve Calcium Score APPLE Score ASCVD (Pooled Cohort)AVA (Continuity Equation)BAG-AHF Score Biplane Simpson EF Blood Pressure Percentiles Brugada Criteria (VT vs SVT)Cardiac Output Index CHA2DS2-VASc CHADS2 Cornell Voltage Criteria CRUSADE Bleeding Score DAPT Score DASI Duke Treadmill Score E/A Ratio EDACS Score EHMRG EHRA Score Embolic Risk Score EROA (PISA Method)FFR (Fractional Flow Reserve)Fick Cardiac Output Framingham 10-Year Risk Friedewald LDL Equation Gorlin Equation GRACE Score Gupta MICA (NSQIP)GWTG-HF Score H2FPEF Score Hakki Formula HAS-BLED HEART Pathway HEART Score HEMORR2HAGES hs-Troponin 0h/1h ESC Algorithm iFR INTERCHEST Score Killip Classification Lee's RCRI LV Mass Index LV Stroke Work Index MAGGIC Risk Score MAP Calculator Martin/Hopkins LDL Modified Duke Criteria Modified Sgarbossa Criteria MVA (Pressure Half-Time)Non-HDL Cholesterol NT-proBNP Age-Adjusted Thresholds ORBIT Score Ottawa Heart Failure Risk PREVENT Equations Pulse Pressure PVR Calculator PVR Index QRISK3 QTc (Bazett)QTc (Fridericia)REVEAL 2.0 Score REVEAL Lite 2 Reynolds Risk Score ROSI RVSP Calculator Schwartz Score (LQTS)SCORE2 Seattle Heart Failure Model (SHFM)Sgarbossa Criteria Shock Index Sokolow-Lyon Voltage Stroke Volume Index SVR Calculator SYNTAX Score SYNTAX Score II TAPSE Teichholz Formula TIMI (STEMI)TIMI (UA/NSTEMI)Troponin Delta Calculator Valvular Gradients Vancouver Chest Pain Rule Vereckei Algorithm WATCHDM Score Wilkins Score Wood Units Calculator

Recent Journal Updates

DiabetologiaJun 5, 2026

MASLD, diabetes and PMOS across the female life stages

Clinical Context

We think this might be relevant to the clinical guidance for Schwartz Score (Long QT Syndrome).

CancerJun 5, 2026

Correction to “Clinical, genetic, and familial features of POT1 tumor predisposition syndrome”

Clinical Context

We think this might be relevant to the clinical guidance for Schwartz Score (Long QT Syndrome).

Intensive Care MedicineJun 2, 2026

Nutrition support in the ICU: current evidence and evolving standards

Clinical Context

We think this might be relevant to the clinical guidance for Schwartz Score (Long QT Syndrome).

Schwartz Score (LQTS)

Schwartz Score (LQTS): Diagnostic probability of congenital Long QT Syndrome (LQTS).

ECG Findings

QTc Duration (Bazett)

Torsades de pointes (+2)

T wave alternans (+1)

Notched T wave in 3 leads (+1)

Low heart rate for age (+0.5)

Clinical & Family History

Syncope (Not scored if TdP is Yes)

Congenital deafness (+0.5)

Family member with definite LQTS (+1)

Unexplained SCD in immediate family < 30y (+0.5)

Guidelines & Evidence

Verified

Last Review: 2026

When to Use

Patients with an incidentally discovered prolonged QTc on a resting 12-lead ECG (>450 ms in men, >460 ms in women)

Patients presenting with unexplained syncope, especially if provoked by exercise, emotion, or auditory stimuli

Family members of patients with known Long QT Syndrome (LQTS) or unexplained sudden cardiac death

Do Not Use If

The QT prolongation is clearly acquired (e.g., secondary to hypokalemia, hypomagnesemia, or QT-prolonging drugs like haloperidol, amiodarone, or certain macrolides). The Schwartz score is designed to estimate the probability of CONGENITAL LQTS. Secondary causes must be ruled out first.

Last Comprehensive Review: 2026

Guidelines & Evidence

Verified

Last Review: 2026

When to Use

Pre-genetic test probability estimation for congenital Long QT Syndrome (LQTS) in symptomatic or asymptomatic individuals with prolonged QTc.

Supporting clinical diagnosis of LQTS in individuals with QTc borderline (440–499ms) where cause is uncertain.

Triaging which patients warrant genetic testing for KCNQ1 (LQT1), HERG/KCNH2 (LQT2), and SCN5A (LQT3).

Endorsed in HRS/EHRA/APHRS 2013 Expert Consensus and ACC/AHA/HRS 2017 arrhythmia guidelines.

Last Comprehensive Review: 2026

Related Cardiovascular Tools

PVR Index

ABC-AF Bleeding Score

ABC-AF Stroke Score

Modified Duke Criteria

H2FPEF Score

QTc

Aortic Valve Calcium Score

CHA2DS2-VASc

LV Mass Index

Wilkins Score

Cardiovascular Calculators Critical Care Calculators Emergency Medicine Calculators

Have feedback about this calculator?Let us know.

Recent Journal Updates

DiabetologiaJun 5, 2026

MASLD, diabetes and PMOS across the female life stages

Clinical Context

We think this might be relevant to the clinical guidance for Schwartz Score (Long QT Syndrome).

CancerJun 5, 2026

Correction to “Clinical, genetic, and familial features of POT1 tumor predisposition syndrome”

Clinical Context

We think this might be relevant to the clinical guidance for Schwartz Score (Long QT Syndrome).

Intensive Care MedicineJun 2, 2026

Nutrition support in the ICU: current evidence and evolving standards

Clinical Context

We think this might be relevant to the clinical guidance for Schwartz Score (Long QT Syndrome).

Schwartz Score (LQTS)

Schwartz Score (LQTS): Diagnostic probability of congenital Long QT Syndrome (LQTS).

ECG Findings

QTc Duration (Bazett)

Torsades de pointes (+2)

T wave alternans (+1)

Notched T wave in 3 leads (+1)

Low heart rate for age (+0.5)

Clinical & Family History

Syncope (Not scored if TdP is Yes)

Congenital deafness (+0.5)

Family member with definite LQTS (+1)

Unexplained SCD in immediate family < 30y (+0.5)

Guidelines & Evidence

Verified

Last Review: 2026

When to Use

Patients with an incidentally discovered prolonged QTc on a resting 12-lead ECG (>450 ms in men, >460 ms in women)

Patients presenting with unexplained syncope, especially if provoked by exercise, emotion, or auditory stimuli

Family members of patients with known Long QT Syndrome (LQTS) or unexplained sudden cardiac death

Do Not Use If

Last Comprehensive Review: 2026

Guidelines & Evidence

Verified

Last Review: 2026

When to Use

Pre-genetic test probability estimation for congenital Long QT Syndrome (LQTS) in symptomatic or asymptomatic individuals with prolonged QTc.

Supporting clinical diagnosis of LQTS in individuals with QTc borderline (440–499ms) where cause is uncertain.

Triaging which patients warrant genetic testing for KCNQ1 (LQT1), HERG/KCNH2 (LQT2), and SCN5A (LQT3).

Endorsed in HRS/EHRA/APHRS 2013 Expert Consensus and ACC/AHA/HRS 2017 arrhythmia guidelines.

Last Comprehensive Review: 2026

Related Cardiovascular Tools

PVR Index

ABC-AF Bleeding Score

ABC-AF Stroke Score

Modified Duke Criteria

H2FPEF Score

QTc

Aortic Valve Calcium Score

CHA2DS2-VASc

LV Mass Index

Wilkins Score

Cardiovascular Calculators Critical Care Calculators Emergency Medicine Calculators

Have feedback about this calculator?Let us know.