An external pacing system, comprising: electrodes configured to deliver electrical stimulations to a patient via electrode leads; a first biological sensor configured to sense a first biological parameter of the patient; a second biological sensor configured to sense a second biological parameter of the patient, the second biological parameter being different than the first biological parameter; a discharge circuit; and a processor, wherein the processor is configured for: controlling the discharge circuit to provide a first electrical stimulation at a current level to the electrodes at a first time; receiving, from the first biological sensor at a second time after the first time, first data associated with the first biological parameter; receiving, from the second biological sensor at the second time, second data associated with the second biological parameter, wherein the first biological parameter corresponds to ECG, SpO 2, NIBP, invasive blood pressure, ETCO 2, rSO 2, or ventilation, and wherein the second biological parameter corresponds to a different one of ECG, SpO 2, NIBP, invasive blood pressure, ETCO 2, rSO 2, or ventilation than the first biological parameter; determining, based on the first data and the second data received at the second time, a likelihood that the first electrical stimulation has caused capture of a heart of the patient; comparing the likelihood to a threshold likelihood; and responsive to determining that the likelihood is greater than or equal to the threshold likelihood, controlling the discharge circuit to provide a second electrical stimulation at the current level by the discharge circuit to the electrodes. electrodes configured to deliver electrical stimulations to a patient via electrode leads; a first biological sensor configured to sense a first biological parameter of the patient; a second biological sensor configured to sense a second biological parameter of the patient, the second biological parameter being different than the first biological parameter; a discharge circuit; and a processor, wherein the processor is configured for: controlling the discharge circuit to provide a first electrical stimulation at a current level to the electrodes at a first time; receiving, from the first biological sensor at a second time after the first time, first data associated with the first biological parameter; receiving, from the second biological sensor at the second time, second data associated with the second biological parameter, wherein the first biological parameter corresponds to ECG, SpO 2, NIBP, invasive blood pressure, ETCO 2, rSO 2, or ventilation, and wherein the second biological parameter corresponds to a different one of ECG, SpO 2, NIBP, invasive blood pressure, ETCO 2, rSO 2, or ventilation than the first biological parameter; determining, based on the first data and the second data received at the second time, a likelihood that the first electrical stimulation has caused capture of a heart of the patient; comparing the likelihood to a threshold likelihood; and responsive to determining that the likelihood is greater than or equal to the threshold likelihood, controlling the discharge circuit to provide a second electrical stimulation at the current level by the discharge circuit to the electrodes. controlling the discharge circuit to provide a first electrical stimulation at a current level to the electrodes at a first time; receiving, from the first biological sensor at a second time after the first time, first data associated with the first biological parameter; receiving, from the second biological sensor at the second time, second data associated with the second biological parameter, wherein the first biological parameter corresponds to ECG, SpO 2, NIBP, invasive blood pressure, ETCO 2, rSO 2, or ventilation, and wherein the second biological parameter corresponds to a different one of ECG, SpO 2, NIBP, invasive blood pressure, ETCO 2, rSO 2, or ventilation than the first biological parameter; determining, based on the first data and the second data received at the second time, a likelihood that the first electrical stimulation has caused capture of a heart of the patient; comparing the likelihood to a threshold likelihood; and responsive to determining that the likelihood is greater than or equal to the threshold likelihood, controlling the discharge circuit to provide a second electrical stimulation at the current level by the discharge circuit to the electrodes.