A subject who was free of a Model 4396 lead related complication by the one month visit. All adverse events (AE) in the time frame were recorded at the subject's center and assessed by a centralized Adverse Event Advisory Committee (AEAC). The AEAC determined whether an AE was a complication and whether the event was related to the Model 4396 lead. A complication is an AE that results in death, termination of significant device function or invasive intervention (any therapy that penetrates the skin including administration of intramuscular (IM) and parenteral (IV) fluids).

Subjects who underwent a Model 4396 left ventricular (LV) lead implant attempt and had a 1 month follow-up visit.

Subjects' distal tip electrode voltage threshold was collected at the one month visit. The Model 4396 was considered effective if the mean voltage threshold was less than 3.0 Volts. Voltage threshold was collected using LV tip to Right Ventricular (RV) coil configuration at 0.5 milliseconds [ms]. Voltage threshold is the minimum energy required from the device to consistently pace the ventricle.

Only subjects with pacing thresholds captured at 0.5 ms were included in the analysis.

Subject's proximal ring electrode voltage threshold was collected at the three months visit. The Model 4396 was considered effective if the mean voltage threshold was less than 3.0 Volts.

Subjects with ring electrode threshold captured at 0.5 ms at 3-month

A successful implant occurs when the Model 4396 lead is implanted in a left ventricular vein and functions appropriately. A Model 4396 implant attempt was defined as any time when a Model 4396 lead was introduced into the body.

Subjects who underwent Model 4396 LV implant attempt.

A successful implant after cannulation occurs when the coronary sinus (CS) is successfully cannulated and a left ventricular lead (any transvenous LV lead) is implanted in a left ventricular vein and functions appropriately. An implant attempt of any transvenous LV lead was defined as any time when a transvenous LV lead was introduced into the body.

Subjects with successful CS cannulation after an implant attempt.

A successful implant occurs when any transvenous LV lead is implanted in a left ventricular vein functions appropriately.

Subjects who underwent an implant attempt.

A successful implant occurs when any Medtronic Attain Family LV Lead is implanted in a left ventricular vein and functions appropriately. The Attain Family leads include the following models: 4193, 4194, 4195, 4196, and 4396.

Subjects who underwent an implant attempt.

Cannulation time was defined as the time from insertion of the first coronary sinus (CS) cannulation catheter to the first successful CS cannulation.

Subjects successfully implanted with a Model 4396 lead.

The total time the fluoroscope was imaging (not including biplane fluoroscopy time).

Subjects successfully implanted with a Model 4396 lead. Note that one subject's standard fluoroscopy time was not collected and a study deviation was reported.

Model 4396 lead placement time was defined as the time from insertion of the successfully implanted lead to the time when it was placed in the first acceptable pacing location.

Subjects successfully implanted with a Model 4396 lead. Note that one subject's LV Lead placement time was permanently missing and a study deviation was reported.

Total operation time was defined as time from initial incision to final closure.

Subjects successfully implanted with a Model 4396 lead.

Implant lead handling characteristics were qualitatively assessed through physician feedback on the Implant Case Report Form (CRF). Physicians were asked for their overall assessment of the lead and results were categorized as acceptable or unacceptable. The number of acceptable responses are summarized.

Subjects who underwent a Model 4396 left ventricular lead implant attempt.

Subjects' voltage threshold in the bipolar configuration was collected at the one month visit. The Model 4396 was considered effective if the mean voltage threshold (at 0.5 milliseconds [ms]) is less than or equal to 4.0 Volts.

Subjects that were implanted with a Model 4396 lead and completed the 1 month visit

Tip electrode voltage threshold at 0.5 ms was collected at implant, pre-hospital discharge and all scheduled follow-up visits. Voltage threshold values at the 6 month visit are summarized.

Subjects with tip electrode threshold captured at 0.5 ms at 6 month

Subjects' tip electrode pacing impedance (a measure of electrical resistance) was measured at implant, pre-hospital discharge and all scheduled follow-up visits. Pacing impedance at the 6 month visit is presented here.

Subjects with tip electrode pacing impedance at 6 month

Tip electrode sensing, measured by R-wave amplitude, for the Model 4396 was collected at implant, pre-hospital discharge and all scheduled follow-up visits. Measurements at the 6 month visit are presented here. Sensing is the minimum energy produced by the left ventricle of the heart that the device can sense.

Subjects with tip electrode R-wave amplitude at 6 month

Ring electrode voltage threshold at 0.5 ms was collected at implant, pre-hospital discharge and all scheduled follow-up visits. Voltage threshold at the 6 month visit is presented here.

Subjects with ring electrode threshold captured at 0.5 ms at 6 month

Subjects' ring electrode pacing impedance was measured at implant, pre-hospital discharge and all scheduled follow-up visits. Pacing impedance at the 6 month visit is presented here.

Subjects with ring electrode pacing impedance at 6 month

Ring electrode sensing, measured by R-wave amplitude, for the Model 4396 was collected only at the implant procedure because the devices allowed in this study are not programmable to collect sensing measurements using the ring electrode. The analyzer was used to collect measurements.

Subjects with ring electrode R-wave amplitude at implant

Bipolar voltage threshold at 0.5 ms was collected at implant, pre-hospital discharge and all scheduled follow-up visits. Voltage threshold at the 6 month visit is reported here.

Subjects with bipolar configuration threshold captured at 0.5 ms at 6 month

Subjects' bipolar pacing impedance was measured at implant, pre-hospital discharge and all scheduled follow-up visits. Pacing impedance at the 6 month visit is presented here.

Subjects with bipolar configuration pacing impedance at 6 month

Bipolar sensing, measured by R-wave amplitude, for the Model 4396 was collected at implant, pre-hospital discharge and all scheduled follow-up visits. Measurements at the 6 month visit are presented here.

Subjects with bipolar configuration electrode R-wave amplitude at 6 month.