JMIR Publications

ABSTRACT

Background:

Palpitations, syncope and presyncope, and undiagnosed atrial fibrillation (AF) are common and diagnostically frustrating presentations in primary care. The resting 12-lead electrocardiogram (ECG) is diagnostic in only a minority of cases, and ambulatory cardiac monitoring is frequently both under- and over-used. Primary care already relies on brief patient-facing case-finding instruments for several conditions, but none is in routine use for occult arrhythmia. .

Conclusions:

CARDIAQ operationalizes guideline-concordant reasoning and real-world monitoring yield into a readable pre-visit aid for primary care. Its weights and thresholds are evidence-informed but not empirically calibrated; the instrument is not diagnostic and must not be used to direct management in its current form. A prospective, multisite diagnostic-accuracy and calibration study with blinded reference-standard ambulatory monitoring, reported to STARD 2015 and TRIPOD+AI, is the necessary next step before clinical adoption.

Objective:

Our study aimes to document transparently how professional-society guidelines, real-world diagnostic-yield evidence, and landmark detection trials were combined to construct CARDIAQ (Cardiac Arrhythmia Risk and Detection Investigation Assessment Questionnaire), an 8-item plain-language patient self-assessment for completion before or during a primary care visit, and to specify the prospective validation study required before clinical use.

Methods:

CARDIAQ items, response options, ordinal point weights, and risk bands were generated by mapping candidate variables to 3 concordant evidence streams: (1) professional-society guidelines for palpitations, syncope, bradycardia, and AF from the American College of Cardiology, American Heart Association, Heart Rhythm Society, European Society of Cardiology, European Heart Rhythm Association, and International Society for Holter and Noninvasive Electrocardiology; (2) reported real-world evidence on the diagnostic yield of ambulatory ECG by symptom frequency, comorbidity burden, and monitoring duration; and (3) landmark detection trials (CRYSTAL-AF, STROKE-AF, EMBRACE, LOOP, mSToPS, REHEARSE-AF) and established risk instruments (CHA2DS2-VASc, Canadian Syncope Risk Score, CHARGE-AF). Sources were selected purposively, not by systematic search. Point weights were assigned by evidence-anchored expert judgment; no derivation cohort was used and no weights were fitted to an observed outcome.

Results:

The instrument comprises 8 items: palpitation character and frequency; syncope, presyncope, or unexplained falls; new or unexplained fatigue, dyspnea, chest pain, or cognitive change; prior cardiac or cerebrovascular diagnoses; comorbidities; family history of early sudden cardiac death or a prior abnormal 12-lead ECG; age band; and sex at birth. Item weights (0-4) are summed to a total score stratified into 5 bands (very low, 0-3; low, 4-7; medium-high, 8-12; high, 13-17; very high, 18 or greater), each mapped to a graded action from routine follow-up to prompt specialist referral. A separate red-flag panel overrides the score and directs the patient to emergency care irrespective of the total. Every item is traceable to a specific guideline recommendation, yield dataset, or trial in an item-by-item derivation table. No discrimination, calibration, sensitivity, or specificity estimates exist for the instrument.

Conclusions:

CARDIAQ operationalizes guideline-concordant reasoning and real-world monitoring yield into a readable pre-visit aid for primary care. Its weights and thresholds are evidence-informed but not empirically calibrated; the instrument is not diagnostic and must not be used to direct management in its current form. A prospective, multisite diagnostic-accuracy and calibration study with blinded reference-standard ambulatory monitoring, reported to STARD 2015 and TRIPOD+AI, is the necessary next step before clinical adoption.