A 57-year-old female patient with non-ischaemic cardiomyopathy, no other comorbidities, presented with dyspnoea New York Heart Association (NYHA) class III, and on optimal heart failure medications including angiotensin-converting enzyme inhibitor, β-blocker, mineralocorticoid receptor blocker, and loop-diuretic for 1 year. Physical examination revealed the following results: pulse was 105 b.p.m.; blood pressure was 100/70 mmHg; and congested neck veins with mild bilateral lower limb oedema. Electrocardiogram (ECG) showed left bundle branch block with QRS duration 150 ms () without remarkable improvement. She was evaluated by echocardiography that revealed a dilated LV with LV ejection fraction (EF) = 25% by 2D, severe mitral and tricuspid regurgitation with mild pulmonary hypertension. Assessment of mechanical dyssynchrony revealed increased septa-to-posterior wall delay (170 ms) (). Computed tomography coronary angiography was done to rule out coronary artery stenosis. Patient was a candidate for CRT. During the procedure, the patient was in conscious sedation. After sterilization and preparation of the patient, left pectoral incision was performed for cannulation and wiring of left subclavian vein. Coronary sinus was cannulated successfully using a decapolar non-deflectable electrophysiological catheter (Response-Decapolar CSL-Catheter 6-F—St. Jude Medical) then peel away CS catheter was introduced over it. After successful cannulation of the CS, coronary venography showed two branches; a great cardiac vein, and a small-sized lateral branch with a proximal kink (). With an advancing CS sheath along the great cardiac vein, venography demonstrated a large posterolateral vein that fills retrogradely with marked proximal tortuosity (). Wiring of the lateral branch was done using PT2 LS 0.014-inch percutaneous transluminal coronary angioplasty (PTCA) wire (Boston Scientific) but the lead position was unstable due to the small size of the vein in addition to phrenic nerve stimulation. We shifted to cannulation of the posterolateral vein that was wired with difficulty using PT2 LS PTCA wire 0.014-inch (Boston Scientific). Advancing the LV lead over the wire failed so, a compliant coronary balloon, Maverick PTCA Balloon Catheter (Boston Scientific) 1.5 × 15 mm was easily advanced to the distal segment of the vein. Balloon was inflated up to 8 ATM at posterolateral vein ostium trying to advance the lead along the PTCA wire, but again we failed to insert the lead (). Another wire Asahi Intermediate Guide Wire 0.014-inch (Asahi Intec, Japan) advanced (buddy wire and anchor technique) for sheath stability and facilitation of CS lead insertion were used. Buddy wire technique was tried using two angioplasty wires (PT2 MS PTCA wire 0.014-inch and Asahi Intermediate Guide Wire 0.014-inch) to straighten the posterolateral vein. The anchor technique using Maverick PTCA Balloon positioned at the distal part of the posterolateral vein and its shaft held with backward force. Both techniques failed also to implant the lead. We failed to cannulate the vein using a sub-selector (). Owing to venous tortuosity and severely competent valve evidenced by late venous filling in addition to trials of all available interventions, we decided to use balloon-assisted tracking (BAT) to overcome the competent valve. Maverik non-compliant (NC) PTCA Balloon Catheter (Boston Scientific) 2 × 20 mm was used protruding from the sub-selector and inflated at 12 ATM and both the sub-selector and the balloon were advanced over the PTCA Asahi Intermediate Guide Wire to pass both the competent valve and the tortuous segment as well as to prevent CS dissection (Razor effect). The sub-selector successfully passed and cannulated the posterolateral vein, and then the LV lead (St. Jude Medical—QUICKFLEX-Left-Heart Lead-86 cm) was implanted easily and finally through it ( and ). Good sensing and pacing parameters without diaphragmatic stimulation were obtained. Lastly, the right ventricular (RV) lead (St. Jude Medical—Tendril STS Pacing Lead, 58 cm) was conventionally implanted at the RV apex then the right atrial (RA) lead was implanted at the right atrial appendage (St. Jude Medical—Tendril STS pacing lead, 52 cm). All electrodes were connected to a biventricular pacemaker battery (St. Jude Medical—Allure RF) that was implanted subcutaneously in the pocket. Post-implantation ECG showed QRS duration of 92 ms with dominant R in V1. Follow-up of the patient after 3 then 6 months showed that the patient had NYHA class II, EF improved to 35 then 38% and all implanted leads were still in place.